Dissertations / Theses on the topic 'User tasks'

The need for search often arises from a broad range of complex information needs or tasks (such as booking travel, buying a house, etc.) which lead to lengthy search processes characterised by distinct stages and goals. While existing search systems are adept at handling simple information needs, they offer limited support for tackling complex tasks. Accurate task representations could be useful in aptly placing users in the task-subtask space and enable systems to contextually target the user, provide them better query suggestions, personalization and recommendations and help in gauging satisfaction. The major focus of this thesis is to work towards task based information retrieval systems - search systems which are adept at understanding, identifying and extracting tasks as well as supporting user’s complex search task missions. This thesis focuses on two major themes: (i) developing efficient algorithms for understanding and extracting search tasks from log user and (ii) leveraging the extracted task information to better serve the user via different applications. Based on log analysis on a tera-byte scale data from a real-world search engine, detailed analysis is provided on user interactions with search engines. On the task extraction side, two bayesian non-parametric methods are proposed to extract subtasks from a complex task and to recursively extract hierarchies of tasks and subtasks. A novel coupled matrix-tensor factorization model is proposed that represents user based on their topical interests and task behaviours. Beyond personalization, the thesis demonstrates that task information provides better context to learn from and proposes a novel neural task context embedding architecture to learn query representations. Finally, the thesis examines implicit signals of user interactions and considers the problem of predicting user’s satisfaction when engaged in complex search tasks. A unified multi-view deep sequential model is proposed to make query and task level satisfaction prediction.

The proliferation of small devices and the advancements in various technologies have introduced the concept of pervasive environments. In these environments, user tasks can be executed by using the deployed components provided by devices with different capabilities. One appropriate paradigm for building user tasks for pervasive environments is Service-Oriented Architecture (SOA). Using SOA, user tasks are represented as an assembly of abstract components (i.e., services) without specifying their implementations, thus they should be resolved into concrete components. The task resolution involves automatic matching and selection of components across various devices. For this purpose, we present an approach that allows for each service of a user task, the selection of the best device and component by considering the user preferences, devices capabilities, services requirements and components preferences. Due to the dynamicity of pervasive environments, we are interested in the continuity of execution of user tasks. Therefore, we present an approach that allows components to monitor locally or remotely the changes of properties, which depend on. We also considered the adaptation of user tasks to cope with the dynamicity of pervasive environments. To overcome captured failures, the adaptation is carried out by a partial reselection of devices and components. However, in case of mismatching between an abstract user task and a concrete level, we propose a structural adaptation approach by injecting some defined adaptation patterns, which exhibit an extra-functional behavior. We also propose an architectural design of a middleware allowing the task's resolution, monitoring of the environment and the task adaptation. We provide implementation details of the middleware's components along with evaluation results

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 70).
In this thesis, I describe how I designed and built multiple components and extensions to App Inventor 2 that will allow application builders to create custom services and background tasks and to build applications that can interact with these services and tasks. Previously, the App Inventor platform only supported the creation of applications which had a screen in the foreground at all times. As such, the main abstraction of App Inventor was this notion of a "Screen". These screens could launch certain tasks to run in the background, but they were limited to the few tasks that were exposed by the App Inventor interface. Application builders could not design and customize their own background tasks. This restricted App Inventor users from building certain types of applications, for example, a music player application or an application that has heavy network communication. To enable users to build such applications, I extended the App Inventor platform to expose a "Task" object in addition to the existing "Screen" object. I created a messaging system which would allow Screens and Tasks to communicate with each other. I also developed additional task components that could be contained in these new Task objects. Users can customize the functionality of Tasks by putting together multiple task components. In this way, App Inventor users can now build more functional applications and explore a part of the Android SDK that was previously out of reach.
by Vedha Sayyaparaju.
M. Eng.

La sélection de cibles en mouvement est une tâche courante et complexe dans l'interaction homme-machine (IHM) en général et en particulier dans le domaine de la réalité virtuelle (RV). La prédiction de l'action est une solution intégrale pour aborder les problèmes liés à l'interaction. Cependant, les techniques actuelles de prédiction sont basées sur le suivi continu des actions de l'utilisateur sans prendre en compte la possibilité que les actions d'atteinte d'une cible puissent avoir une composante importante préprogrammée—cette théorie est appelé la théorie du contrôle préprogrammé.En se basant sur la théorie du contrôle préprogrammé, cette thèse explore la possibilité de prédire les actions, avant leur exécution, de sélection d'objets en mouvement. Plus spécifiquement, trois niveaux de prédiction d'action sont étudiés : 1) la performance des actions, mesurée par le temps de mouvement (TM) nécessaire pour atteindre une cible, 2) la difficulté prospective (DP), qui représente la difficulté subjective de la tâche estimée avant son exécution, 3) l'intention de l'utilisateur, qui indique la cible visée par l'utilisateur.Dans le cadre de cette thèse, des modèles de prédiction d'intention sont développés à l'aide des arbres de décision ainsi que des fonctions de classement—ces modèles sont évalués dans deux expériences en RV. Des modèles 1-D et 2-D de DP pour des cibles en mouvement basés sur la loi de Fitts sont développés et évalués dans une expérience en ligne. Enfin, des modèles de TM avec les mêmes caractéristiques structurelles des modèles de DP sont évaluées dans une expérience 3-D en RV
Selection of moving targets is a common, yet complex task in human–computer interaction (HCI), and more specifically in virtual reality (VR). Action prediction has proven to be the most comprehensive enhancement to address moving-target selection challenges. Current predictive techniques, however, heavily rely on continuous tracking of user actions, without considering the possibility that target-reaching actions may have a dominant pre-programmed component—this theory is known as the pre-programmed control theory.Thus, based on the pre-programmed control theory, this research explores the possibility of predicting moving-target selection prior to action execution. Specifically, three levels of action prediction are investigated: 1) action performance measured as the movement time (MT) required to reach a target, 2) prospective difficulty (PD), i.e., subjective assessments made prior to action execution; and 3) intention, i.e., the target that the user plans to reach.In this dissertation, intention prediction models are developed using decision trees and scoring functions—these models are evaluated in two VR studies. PD models for 1-D, and 2-D moving- target selection tasks are developed based on Fitts' Law, and evaluated in an online experiment. Finally, MT models with the same structural form of the aforementioned PD models are evaluated in a 3-D moving-target selection experiment deployed in VR

The purpose of this qualitative, multi-case study is to identify the traits three middle school classroom teachers share, which seemingly enable them to successfully engage their students in performance-based activities and assessments. This study investigates the research behind the use of performance tasks, authentic learning and assessment and connects the data gleaned from observations and interviews with participants and administrators to the literature review. Data analysis and summations connect performance tasks to authentic learning but also identify more subjective traits such as relationship building, riskiness in instructional methodology, and the innate skills of a teacher, which appear to enhance students’ learning experiences. Students observed in the classrooms are asked not only to know content and cultivate an appropriate skill base, but also asked to use that knowledge and those skills to solve real-world problems. Data from the three participants not only illustrates the findings of other relevant research, but characterizes the types of teachers who inspire students to perform on a more complex level in order to solve complex problems.

doi:10.1016/j.intcom.2004.04.008
This paper addresses issues raised by the ever-expanding role of email as a multi-faceted application that combines communication, collaboration, and task management. Individual differences analysis was used to contrast two email user interfaces in terms of their demands on users. The results of this analysis were then interpreted in terms of their implications for designing more inclusive interfaces that meet the needs of users with widely ranging abilities. The specific target of this research is the development of a new type of email message representation that makes pending tasks more visible. We describe a study that compared a new way of representing tasks in an email inbox, with a more standard representation (the Microsoft Outlook inbox). The study consisted of an experiment that examined how people with different levels of three specific cognitive capabilities (flexibility of closure, visual memory, and working memory) perform when using these representations. We then identified combinations of representation and task that are disadvantageous for people with low levels of the measured capabilities.

Ubiquitous computing (Ubicomp) increases in proliferation. Multiple and ever growing in numbers, computational devices are now at the users' disposal throughout the physical environment, while simultaneously being effectively invisible. Consequently, a significant challenge is service discovery. Services may for instance be physical, such as printing a document, or virtual, such as communicating information. The existing solutions, such as Bluetooth and UPnP, address part of the issue, specifically low-level physical interconnectivity. Still absent are solutions for high-level challenges, such as connecting users with appropriate services. In order to provide appropriate service offerings, service discovery in Ubicomp must take the users' context, tasks, goals, intentions, and available resources into consideration. It is possible to divide the high-level service-discovery issue into two parts; inadequate service models, and insufficient common-sense models of human activities.

This thesis contributes to service discovery in Ubicomp, by arguing that in order to meet these high-level challenges, a new layer is required. Furthermore, the thesis presents a prototype implementation of this new service-discovery architecture and model. The architecture consists of hardware, ontology-layer, and common-sense-layer. This work addresses the ontology and common-sense layers. Subsequently, implementation is divided into two parts; Oden and Magubi. Oden addresses the issue of inadequate service models through a combination of service-ontologies in concert with logical reasoning engines, and Magubi addresses the issue of insufficient common-sense models of human activities, by using common sense models in combination with rule engines. The synthesis of these two stages enables the system to reason about services, devices, and user expectations, as well as to make suitable connections to satisfy the users' overall goal.

Designing common-sense models and service ontologies for a Ubicomp environment is a non-trivial task. Despite this, we believe that if correctly done, it might be possible to reuse at least part of the knowledge in different situations. With the ability to reason about services and human activities it is possible to decide if, how, and where to present the services to the users. The solution is intended to off-load users in diverse Ubicomp environments as well as provide a more relevant service discovery.

Report code: LiU-Tek-Lic-2007:14.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.
Includes bibliographical references (p. 153-155).
by David François Huynh.
S.M.

Information retrieval (IR) is an important part of many tasks performed by people when they use computers. However, most IR research and theory isolates the IR component from the tasks performed by users. This is done by expressing user needs as a query performed on a database. In contrast this dissertation investigates the design and evaluation of information retrieval systems where the information retrieval mechanisms remain embedded in the user tasks. While there are a many different types of user tasks performed with computers we can specify common requirements for the IR needed in most tasks. There are both user interface and machine processing requirements. For user interfaces it is desirable if users interact directly with information databases, keep control of the interaction and are able to perform IR in a timely manner. Machine processing has to be within the capabilities of machines yet must fit with human perceptions and has to be efficient in both storage and computation. Given the overall requirements, the dissertation gives a particular implementation for how to embed IR in tasks. The implementation uses a vector representation for objects and organises the objects in a near neighbour data structure. Near neighbours are defined within the context of the tasks the users wish to achieve. While the implementation could use many different finding mechanisms, it emphasises a constructive solution building approach with localised browsing in the database. It is shown how the IR implementation fits with the overall task activities of the user. Much of the dissertation examines how to evaluate embedded IR. Embedded IR requires testing users' task performance in both real experiments and thought experiments. Implementation is tested by finding known objects, by validating the machine representations and their correspondence with human perceptions and by testing the machine performance of the implementation. Finally implications and extensions of the work arc explored by looking at the practicality of the approach, other methods of investigation and the possibility of building dynamic learning systems that improve with use.

Visual analytics, defined as "the science of analytical reasoning facilitated by interactive visual interfaces," emerged several years ago as a new research field. While it has seen rapid growth for its first five years of existence, the main focus of visual analytics research has been on developing new techniques and systems rather than identifying how people conduct analysis and how visual analytics tools can help the process and the product of sensemaking. The intelligence analysis community in particular has not been fully examined in visual analytics research even though intelligence analysts are one of the major target users for which visual analytics systems are built. The lack of understanding about how analysts work and how they can benefit from visual analytics systems has created a gap between tools being developed and real world practices. This dissertation is motivated by the observation that existing models of sensemaking/intelligence analysis do not adequately characterize the analysis process and that many visual analytics tools do not truly meet user needs and are not being used effectively by intelligence analysts. I argue that visual analytics research needs to adopt successful HCI practices to better support user tasks and add utility to current work practices. As the first step, my research aims (1) to understand work processes and practices of intelligence analysts and (2) to evaluate a visual analytics system in order to identify where and how visual analytics tools can assist. By characterizing the analysis process and identifying leverage points for future visual analytics tools through empirical studies, I suggest a set of design guidelines and implications that can be used for both designing and evaluating future visual analytics systems.

Les Interfaces Cerveaux-Ordinateur (ICO) sont des systèmes qui permettent de manipuler une machine avec sa seule activité cérébrale. Elles sont utilisées pour accomplir des objectifs variés, par exemple afin qu’un amputé puisse manipuler un bras robotique, pour une réhabilitation neuronale en cas d’accident vasculaire cérébral, dans un cadre ludique pour jouer à des jeux vidéo, etc. Une ICO comprend l’acquisition du signal cérébral (le plus souvent par électroencéphalographie, EEG), le décodage et l’interprétation de ce signal, et enfin la production d’un retour sensoriel à l’utilisateur. Ce retour guidera l’utilisateur pour réguler son activité cérébral et apprendre à manipuler la machine. La morphologie du cerveau diffère cependant entre utilisateurs, et les pensées d’un même individu varient au cours du temps. Ces fluctuations rendent les ICO moins performantes, qui sont alors difficiles à utiliser hors des conditions du laboratoire. Nous avons donc besoin d’une machine dynamique, qui puisse s’adapter au cours du temps à son utilisateur. Dans la littérature les approches proposées afin de remédier à ce problème décrivent des machines qui décodent de manière adaptative les signaux EEG, mais ces systèmes ne sont pas assez robustes et ne permettent toujours pas aux ICO d’être utilisées dans la vie quotidienne. L’objectif de cette thèse est d’améliorer les performances et l’utilisabilité des ICO basées sur de l’EEG, en les adaptant de façon innovante aux états et compétences des utilisateurs. Pour ce faire, nous avons premièrement mis en évidence tous les facteurs changeants dans une ICO en définissant trois séquences : 1. Les états psychologiques fluctuants de l’utilisateur qui modifient la signature du signal EEG ; 2. Ce signal qui varie et qui amène la machine à ajuster son décodage ; 3. La tâche qui est présentée à l’utilisateur via le retour sensoriel de la machine, et qui influence à son tour les états psychologiques de l’utilisateur. Nous avons ainsi mis en évidence la possibilité d’adopter un nouvel angle de recherche, en utilisant la tâche adaptative pour diriger les états psychologiques de l’utilisateur et aider ce dernier à manipuler une ICO. Au lieu de seulement adapter le décodage aux signaux cérébraux, nous avons donc considéré l’adaptation de l’interface (via le retour sensoriel produit par la machine) afin d’influencer les signaux et d’en faciliter le décodage. En utilisant des connaissances issues de la psychologie comportementale et des sciences de l’éducation, il est en effet possible de créer des taches et des interfaces qui incitent les utilisateurs à réussir et même à prendre plaisir à utiliser une ICO. Ces différents facteurs, liés à la motivation, participent à produire des signaux plus prédictibles et plus facilement décodables par la machine, augmentant d’autant la performance du système. Nous avons donc formulé une taxonomie des ICO adaptatives en définissant la tâche adaptative comme un nouveau moyen d’améliorer les performances des ICO. Une fois que la taxonomie des ICO adaptatives a été mis en place, nous avons cherché à identifier chez l’utilisateur quel était l’état psychologique optimal qui puisse servire de critère d’optimisation de la tâche. La littérature en psychologie indique que cet état est l’état de flow, un état d’immersion, de contrôle et de plaisir optimal qui incite les gens à se surpasser, quel que soit la tâche, le sexe, la culture ou bien encore l’âge. [...]
Brain-Computer Interfaces (BCIs) are systems that enable a person to manipulate an external device with only brain activity, often using ElectroEncephaloGraphgy (EEG). Although there is great medical potential (communication and mobility assistance, as well as neuro-rehabilitation of those who lost motor functions), BCIs are rarely used outside of laboratories. This is mostly due to users’ variability from their brain morphologies to their changeable psychological states, making it impossible to create one system that works with high success for all. The success of a BCI depends tremendously on the user’s ability to focus to give mental commands, and the machine’s ability to decode such mental commands. Most approaches consist in either designing more intuitive and immersive interfaces to assist the users to focus, or enhancing the machine decoding properties. The latest advances in machine decoding are enabling adaptive machines that try to adjust to the changeable EEG during the BCI task. This thesis is unifying the adaptive machine decoding approaches and the interface design through the creation of adaptive and optimal BCI tasks according to user states and traits. Its purpose is to improve the performance and usability of BCIs and enable their use outside of laboratories. To such end, we first created a taxonomy for adaptive BCIs to account for the various changeable factors of the system. Then, we showed that by adapting the task difficulty we can influence a state of flow, i.e., an optimal state of immersion, control and pleasure. which in turn correlates with BCI performance. Furthermore, we have identified the user traits that can benefit from particular types of task difficulties. This way we have prior knowledge that can guide the task adaptation process, specific to each user trait. As we wish to create a generic adaptation rule that works for all users, we use a probabilistic Bayesian model, called Active Inference used in neuroscience to computationally model brain behavior. When we provide such probabilistic model to the machine, it becomes adaptive in such a way that it mimics brain behavior. That way, we can achieve an automatic co-adaptive BCI and potentially get a step closer into using BCIs in our daily lives

The engagement in multiple activities in the workplace leads to the challenge of managing several tasks. When managing multiple tasks, it may be difficult to remember to complete all tasks. Within an operations team at a hedge fund, there are demands that all trades are reported by the end of the day to the correct prime brokerage. This thesis examines the research question: How can a GUI be designed to remind and aid users to verify that trade information has been managed correctly? The research was conducted at a financial company, and focused on improving the workflow for one of the company’s clients and its operations team. To identify the challenges of a financial operator, contextual inquiries were conducted, followed by a design workshop to generate design ideas. The results were used as inspiration for the prototype of a GUI. The prototype was evaluated through cognitive walkthroughs, expert review, and with end users. The prototype was found to aid financial operators to verify if there was any work left, but the reminder aspect would need to be examined with a real system during an extended period.
Att engagera sig i flertalet aktiviteter på en arbetsplats leder till utmaningen att hantera många uppgifter. När det finns många uppgifter att hantera, kan det vara svårt att komma ihåg att slutföra alla uppgifter. Inom ett operationsteam på en hedgefond finns krav att alla värdepappersaffärer ska vara rapporterade innan dagens slut till rätt huvudmäklarfirma (prime brokerage). Denna uppsats undersöker forskningsfrågan: Hur kan ett GUI designas för att påminna och underlätta för användaren att verifiera att information om värdepappersaffärer har hanterats korrekt? Forskningen genomfördes på ett finansiellt företag och fokuserade på att underlätta arbetsflödet för en av företagets kunder och dess operationsteam. För att identifiera utmaningarna för en finansiell operatör genomfördes kontextuella intervjuer, vilka följdes av en designworkshop för att generera designidéer. Resultaten användes som inspiration till en prototyp för ett GUI. Prototypen utvärderades genom kognitiv genomgång (cognitive walkthrough), expertgranskning och med slutanvändare. Prototypen ansågs underlätta för finansiella operatörer att verifiera om det fanns kvarvarande uppgifter, men påminnelseaspekten skulle behöva undersökas ytterligare med ett fullt utvecklat system under en längre period.

In the past three decades, using Augmented Reality (AR) in repair tasks has received a growing amount of attention from researchers, because AR provides the users with a more immersive experience than traditional methods, e.g., instructional booklets, and audio, and video content. However, traditional methods are mostly used today, because there are several key challenges to using AR in repair tasks. These challenges include device limita- tions, object pose tracking, human-computer interaction, and authoring. Fortunately, the research community is investigating these challenges actively. The vision of this thesis is to move the AR technology towards being widely used in this field. Under this vision, I propose an AR platform for repair tasks and address the challenges of device limitations and authoring. The platform contains a new authoring ap- proach that tracks the real components on the expert’s side to monitor her or his operations. The proposed approach gives experts a novel authoring tool to specify 6DoF movements of a component and apply the geometrical and physical constraints in real-time. To ad- dress the challenge of device limitations, I present a hybrid remote rendering framework for applications on mobile devices. In my remote rendering approach, I adopt a client-server model, where the server is responsible for rendering high-fidelity models, encoding the ren- dering results and sending them to the client, while the client renders low-fidelity models and overlays the high-fidelity frames received from the server on its rendering results. With this configuration, we are able to minimize the bandwidth requirements and interaction latency, since only key models are rendered in high-fidelity mode. I perform a quantitive analysis on the effectiveness of my proposed remote rendering method. Moreover, I conduct a user study on the subjective and objective effects of the remote rendering method on the user experience. The results show that key model fidelity has a significant influence on the objective task difficulty, while interaction latency plays an important role in the subjective task difficulty. The results of the user study show how my method can benefit the users while minimizing resource requirements. By conducting a user study for the AR remote assistance platform, I show that the proposed AR plat- form outperforms traditional instructional videos and sketching. Through questionnaires provided at the end of the experiment, I found that the proposed AR platform receives higher recommendation than sketching, and, compared to traditional instructional videos, it stands out in terms of instruction clarity, preference, recommendation and confidence of task completion. Moreover, as to the overall user experience, the proposed method has an advantage over the video method.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.
Includes bibliographical references (p. 107-108).
Information based tasks rely on software applications that allow users to interact with information in some pre-defined manner deemed appropriate by the application developer or information/content provider. Whereas such an approach facilitates one way of working with the information, it does not (and cannot) take into account the unique needs of the user, e.g., the particular content of interest given the specific task being performed and expertise of the user, information visualization and interaction preferences of the user, etc. As a result, users must perform additional overhead information management activities in working with the software tools in order to accomplish their particular tasks. In this thesis, we advocate breaking the "rigidity" of such applications by allowing users to create and customize their own task-oriented interfaces (information spaces) that aggregate and present task-specific information and tools on the same screen. In developing a system that allows users to tailor an information space in a manner that suits their particular task and preferences, we recognize a set of desirable properties it must have, and the need for it to provide the user customization control over three primary aspects of information in their information space: content, presentation and manipulation. Haystack, a generalized information management system, encompasses many of the desirable properties at the system level and also provides many of the building blocks that are required to give users greater customization control. We thus approach our ultimate goal of enabling users to build and configure a personalized task-oriented interface by providing them with tools situated in Haystack that allow manipulating various primitives that control
(cont.) the three aspects of information spaces. A discussion of the design and implementation of each of the tools is provided. The above solution allows users to develop information spaces that better match their unique conception of the task and eliminate much of the overhead resulting from "rigid" information management tools, resulting in productivity gains in recurring or long-running tasks.
by Karun Bakshi.
S.M.

Cette thèse a été initiée dans un contexte d’amélioration de l'expérience utilisateur (UX) pour l'analyse des données de Business Intelligence en raison de l'augmentation du volume de données liées à cette activité. D'une part, les besoins psychologiques des utilisateurs portent sur la simplification de l’utilisation des applications analytiques, ils font l’objet de plus en plus d’attention ; d'autre part, les tâches qu'ils sont prêts à mener deviennent de plus en plus complexes ce qui peut entraîner une surcharge de mémoire qui influe sur les performances dans leur réalisation. Pour garantir la prise en compte de ces deux aspects, les designers doivent concevoir des interfaces et fournir des informations appropriées qui répondent à la fois aux besoins des utilisateurs et aux nécessités de leur activité. Dans cette recherche, nous nous sommes intéressés à l'amélioration de la reprise de la tâche suite à une suspension ou à une interruption de celle-ci dans le cadre de l’analyse visuelle de données. La nature multitâche des actions des utilisateurs et les capacités limitées de stockage de la mémoire de travail humaine entraînent des difficultés à s’engager de nouveau dans une tâche qui a été interrompue ou suspendue. Il devient donc avantageux de disposer d'un outil de suppléance de la mémoire qui aide les utilisateurs à se remettre à leur tâche dans des conditions optimales.Une revue de la littérature nous a conduit tout d'abord au positionnement de notre recherche vis à vis de l'approche énactive et de la perception sensorimotrice qui considèrent l'outil comme un artefact configurant l'interaction entre l'utilisateur et la tâche, selon deux états, saisi ou déposé. De ce point de vue, nous avons constaté que le modèle de mémoire cognitiviste utilisé couramment ne considère pas le rôle de l’interaction avec le monde extérieur dans la construction de la mémoire, et par conséquent ignore la dimension saisie des supports et outils dans la construction d’une mémoire. Par conséquent, nous proposons de compléter ce modèle avec un modèle de mémoire incarnée, qui ouvre une nouvelle perspective permettant de concevoir un outil de suppléance mémorielle approprié. Enfin, les principes de conception d’IHM et d’UX nous aident à construire une proposition d’outil et à mener un plan d'expérience mettant en avant le lien entre les modifications des conditions de perception et les modifications de la dynamique d’interaction. En conclusion de cette partie, la problématique générale est introduite avec l’exploration, la mise en œuvre et l’évaluation de la proposition. La première expérience, le test pilote, analyse la perception que peuvent avoir des concepteurs naviguant sur des applications interactives. Cette étude nous a aidé à construire un vocabulaire d'évaluation en conception d’un support de suppléance de la mémoire et nous a guidé pour concevoir un processus expérimental en tenant compte de ces critères. Dans une seconde expérience, nous développons un outil basé sur une fonction que nous appelons le "history path". Cet outil permet d’afficher à l’utilisateur, dans une fenêtre spécifique de l’interface, certaines étapes de résolution d’une tâche antérieure effectuée par ce même utilisateur (ou pour simuler une interruption de tâche). Nous avons mis en place une expérience simple (minimaliste) simulant une résolution de problème qui a été enregistrée pour évaluer dans quelle mesure le history path peut aider l'utilisateur à récupérer efficacement une tâche interrompue. La première partie de cette expérience nous permet de confirmer l’utilité potentielle de cette fonction et nous aide à explorer l’espace de conception. Dans la deuxième partie, nous expérimentons deux outils différents basés sur deux représentations de l’history path, une représentation statique et l’autre dynamique. Les résultats de l'évaluation nous amènent à comprendre les conditions techniques d'une expérience positive pour laquelle la reprise de tâche est facilitée
This thesis was initiated in the context of enhancing the user experience for analyzing data due to the increase of the volume of data related to this activity. On the one hand, users’ psychological needs for the simple use of analytic applications are paid more attention than before; on the other hand, the task they are willing to conduct is getting more and more complicated, which may cause memory overload that influences the task performance. To ensure that both aspects are taken into account, the designers should provide a proper information and design a proper interface that meets both users’ needs and the requirements of their activity. In this research, we are interested in improving the task recommitment following a task suspension or interruption in the context of a visual data analysis task. The multitasking nature of user actions and limited storage capacity of human working memory cause difficulties in re-engaging an interrupted or suspended task. Therefore, it is beneficial to have a memory supplementation tool that supports users to recommit their task in optimal conditions. A literature review first leads to the positioning of our research on the enactive approach and sensorimotor perception that consider the tool as an artifact configuring the interaction between the user and the task, in two modes the “put down” mode and the “in hand” mode. From this point of view, we have found that the commonly used cognitive memory model ignores the role of interaction with the external world in the formation of the memory, and consequently ignores the “in hand” dimension of the artifacts in one memory construction. Therefore, we complete this model with the embodied memory, which gives us a new perspective to design an appropriate memory tool that serves as a supplementation of our perceptual system. Finally, the design principles in human-computer interaction and UX helped us build a tool and conduct an experimental plan highlighting the link between changes in perception conditions and changes in the dynamics of interaction. As a conclusion, the research problem is introduced in terms of how we can provide users with a relevant context to recommit to resolving a task after interruption. The design proposal needs to be explored, designed and evaluated. The first experiment, the exploratory study, analyzes the perception of interactive applications by experienced designers. This study helped us construct a vocabulary of evaluation of the design for a memory supplementation support and guided us for the design considering these criteria. In the second experiment, we develop a tool based on a function that we call the “history path”, which permits to show, in a specific window of the user interface, some of the steps of a previous task resolution that a user has performed during previous experience (or to simulate a resolution task interruption). We set up a simple (minimalist) experiment simulating a problem-solving task, which was recorded to evaluate the extent to which a history path support can help the user for efficient recovering of an interrupted task. The first part of this experiment allows us to confirm the potential use of this function and helps us explore the design space. In the second part, we experiment two different tools, based on two history path representations, a static one and a dynamic one. The evaluation results allow us to understand the technical conditions of a positive experience for which task recovery is facilitated. In this second experiment, several means for recording the user experience were mobilized: the evaluation of the durations and gaze frequencies on area of interest in the interface window by eye tracking, the recording of the verbalizations during the RTA (Retrospective Think Aloud) session, and the semantic evaluation

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Bachelors
Engineering and Computer Science
Early Childhood Education

Problem: Designing the user experience is a growing trend in product design; however this trend has not greatly benefited people with impairments and disabilities. There are no practical tools to broadly assist with this issue. There is a need for standardized measures to quantify impairment, a model to predict how designs may perform and a need for data regarding how people with impairments interact with consumer technology. Purpose: To conduct a usability analysis with an industry partner on their powered wheelchair controller using participants with varying impairments. The industry partner was seeking better insight into the benefits of formal user testing. Method: Forty consenting adults were given a score representing their level of impairment using six measures from the International Classification of Functioning (ICF). These measures were identified by the researcher to affect interaction with a device. Performance was measured by time taken to complete tasks, errors made, reported task difficulty and reported controller usability. Results: Performance was reduced in participants with a higher ICF score and age. An ICF score less than or equal to 2 was 117 times more likely to not complete the tasks, greater than or equal to 3 was not able to complete the experiment. Age >50 years took an average 79 seconds longer than <35 years to complete a task and reported greater difficulty, more errors and a lower usability for the controller. Implications: Low to moderate levels of impairment has a significantly negative effect on the usability of common devices. Difficulties were mostly cognitive with participants unable to create an accurate mental model of the system. Participants with lower performance tended to be overly optimistic about their abilities. Mistakes were the greatest source of error followed by lapses and almost no reported or observed slip errors. Original Contribution: The ICF has never been used as a metric for usability testing. This study successfully applied the ICF alongside other measures to prove its validity. Based on the results and current literature the Task Process Model was created to provide a simple and practical way to describe the interaction of people completing a task of basic to moderate complexity.

Many scholarly tasks involve working with contextualized fine-grain information, such as a music professor creating a multimedia lecture on a musical style, while bringing together several snippets of compositions of that style. We refer to such contextualized parts of a larger unit of information (or whole documents), as subdocuments. Current approaches to work with subdocuments involve a mix of paper-based and digital techniques. With the increase in the volume and in the heterogeneity of information sources, the management, organization, access, retrieval, as well as reuse of subdocuments becomes challenging, leading to inefficient and ineffective task execution. A digital library (DL) facilitates management, access, retrieval, and use of collections of data and metadata through services. However, most DLs do not provide infrastructure or services to support working with subdocuments. Superimposed information (SI) refers to new information that is created to reference subdocuments in existing information resources. We combine this idea of SI with traditional DL services, to define and develop a DL with SI (an SI-DL). Our research questions are centered around one main question: how can we extend the notion of a DL to include SI, in order to support scholarly tasks that involve working with subdocuments? We pursued this question from a theoretical as well as a practical/user perspective. From a theoretical perspective, we developed a formal metamodel that precisely defines the components of an SI-DL, building upon related work in DLs, SI, annotations, and hypertext. From the practical/user perspective, we developed prototype superimposed applications and conducted user studies to explore the use of SI in scholarly tasks. We developed SuperIDR, a prototype SI-DL, which enables users to mark up subimages, annotate them, and retrieve information in multiple ways, including browsing, and text- and content-based image retrieval. We explored the use of subimages and evaluated the use of SuperIDR in fish species identification, a scholarly task that involves working with subimages. Findings from the user studies and other work in our research lead to theory- and experiment-based enhancements that can guide design of digital libraries with superimposed information.
Ph. D.

The present thesis aims to deduce tasks and characteristics of end users during the open innovation process on the social web. The social web with its communities, forums and blogs affords new prospects as well as unknown challenges for companies, and at the same has increasingly influenced academic research during the last few years. Especially research regarding communication behaviour on the social web as well as social web technologies has currently progressed well. However, in innovation research, social web technologies are currently primarily used to integrate users into the company’s innovation process, for example through company user toolkits or company innovation communities. In those cases users were excluded from their normal social web environment and integrated into a company’s environment, a sort of laboratory environment. Despite this, the present research project will use the natural behaviour, comments and discussions of users within their social web environment to develop and apply a new mixed-method approach with the aim to deduce tasks and characteristics of innovative end users on the social web. To apply the mixed-method approach within a longitudinal case study and to deduce statements and regularities regarding the innovation process on the social web, it was possible to analyse the end user developer online forum of one of the leading open source CRM software technologies. Based on this analysis, the assumptions from an extensive literature analysis could be verified and extended: it could be shown that the expected single innovative user does not exist. In fact, the process from the initial idea to an innovation requires different users with different characteristics and different points of view. They will be deduced, explained and presented within the present thesis.

[EN] Model-Driven Development (MDD) promotes models as the cornerstone in the software development process, thereby displacing source code as the development process's main feature. Although this model-centric schema claims advantages over traditional software development (e.g., the code could be automatically generated from the models), it does not have the level of adoption that has been expected. The literature review reveals a broad agreement in the fact that end-users may develop and adapt systems themselves but the complexity in modeling standards and the lack of modeling skills prevents their active involvement in modeling tasks of existing MDD processes. To overcome this, end-users should be provided with different modeling languages that use concepts, which fit their particular skills, context and needs. This challenge is the main goal of this thesis, which is addressed by combining the End-user Development and the Model-Driven Development fields. This work starts with the involvement of end-users into the modeling tasks using a tool-supported visual modeling language that allows end-users to select and customize system features of pervasive systems using closer concepts for them. Afterwards, this thesis shows the necessity of enriching existing MDD processes for supporting the development of a new generation of software systems (e.g., smart health) that require expertise in a variety of domains. Consequently, different types of users (e.g., scientists, engineers and end-users) must actively participate in the description of model fragments that depend on their expertise using a different modeling language. Thus, users are able to collaborate to obtain a unified system description. At this point, it becomes necessary to provide mechanisms that transforms models fragments from one modeling language to another, delimits which model fragments are described by a different user, and integrates those model fragments. To provide this, the presented approach encompasses variability management in a novel way to enable collaborative modeling by supporting both the selection of model fragments of the system that may be described using a different modeling language, and the integration of those model fragments once they are described. Furthermore, interoperability mechanisms bridge two different modeling languages in a non-intrusive way with the structure of models by transforming the description of gaps. Thus, our proposal could enrich models of existing MDD processes with model fragments that have been described using a different modeling language, which could make users feel confident to adopt models for describing domain-specific content and could help to adopt MDD processes. The proposal has been validated in three case studies from different levels of complexity and domains: smart home systems, web information systems, and biomechanical protocols. The results have proven the applicability and feasibility of our approach to actively involve different types of users (end- users with software professionals, domain experts with software development experts, and doctors with biomedical engineers, respectively) in model descriptions of existing MDD processes using a different modeling language.
[ES] En el Desarrollo de Software Dirigido por Modelos (DSDM) los modelos son la piedra angular del proceso de desarrollo de software, desplazando así al código fuente como artefacto principal. Aunque este enfoque centrado en modelos ofrece ventajas sobre el desarrollo de software tradicional (por ejemplo, la generación de código de forma automática a partir de los modelos) no tiene el nivel de adopción esperado. La literatura científica revela un amplio acuerdo en el hecho de que los usuarios finales puedan ellos mismos desarrollar y adaptar los sistemas pero la complejidad de los estándares de modelado y la carencia de habilidades de modelado impide su participación activa en procesos DSDM existentes. Para lograrlo, los usuarios finales deben disponer de lenguajes de modelado diferentes con conceptos adaptados a sus habilidades, contexto y necesidades. Este desafío es el objetivo principal de esta tesis que se aborda combinando las ideas del desarrollo orientado al usuario final y el DSDM. Este trabajo comienza involucrando usuarios finales en tareas de modelado con una herramienta que les proporciona un lenguaje de modelado visual para seleccionar y personalizar características de un sistema pervasivo utilizando conceptos familiares para ellos. Después, esta tesis motiva la necesidad de enriquecer procesos de DSDM existentes para soportar el desarrollo de una nueva generación de sistemas software (por ejemplo, salud inteligente) que requieren conocimientos especializados en una variedad de dominios. Consecuentemente, diferentes tipos de usuarios (por ejemplo, científicos, ingenieros y usuarios finales) deben participar activamente en la descripción de fragmentos de modelos que dependen de su experiencia utilizando un lenguaje de modelado diferente. De este modo, los usuarios pueden colaborar para obtener una descripción del sistema unificada. En este punto, es necesario proporcionar mecanismos que transformen e integren los fragmentos de un lenguaje de modelado a otro y delimiten qué fragmentos se describen por un usuario diferente. Para proporcionar esto, la propuesta presentada utiliza la gestión de variabilidad de forma novedosa para permitir modelado colaborativo seleccionando fragmentos de un modelo del sistema que pueden ser descritos utilizando un lenguaje de modelado diferente y, la integración de esos fragmentos una vez que hayan sido descritos. Además, la propuesta utiliza mecanismos de interoperabilidad para conectar dos lenguajes de modelado diferentes transformando la descripción de los fragmentos de una manera no invasiva con su estructura. Por tanto, nuestra propuesta puede enriquecer los modelos de procesos DSDM existentes con fragmentos de modelos que han sido descritos con un lenguaje diferente y esto, podría hacer que los usuarios se sientan seguros al adoptar modelos para describir contenido de dominio específico y podría ayudar a adoptar procesos DSDM. La propuesta ha sido validada en tres casos de estudio con diferentes niveles de complejidad y dominios: sistemas para el hogar inteligente, sistemas de información web y protocolos biomecánicos. Los resultados han demostrado la aplicabilidad y viabilidad de nuestra propuesta para involucrar diferentes tipos de usuarios (usuarios finales con profesionales de software, expertos en el dominio con expertos en desarrollo de software y, médicos con ingenieros biomédicos, respectivamente) en descripciones de modelos de procesos DSDM existentes utilizando un lenguaje de modelado diferente.
[CAT] En el Desenvolupament de Programari Dirigit per Models (DPDM) els models són la pedra angular del procés de desenvolupament de programari, desplaçant així al codi font com a artefacte principal. Encara que aquest enfocament centrat en models ofereix avantatges sobre el desenvolupament de programari tradicional (per exemple, la generació de codi de forma automàtica a partir dels models) no té el nivell d'adopció esperat. La literatura científica revela un ampli acord en el fet que els usuaris finals puguen ells mateixos desenvolupar i adaptar els sistemes però la complexitat dels estàndards de modelatge i la falta d'habilitats de modelatge impedeix la seua participació activa en processos DPDM existents. Per a aconseguir-ho, els usuaris finals han de disposar de llenguatges de modelatge diferents amb conceptes adaptats a les seues habilitats, context i necessitats. Aquest desafiament és l'objectiu principal d'aquesta tesi que s'aborda combinant les idees del desenvolupament orientat a l'usuari final i el DPDM. Aquest treball comença involucrant usuaris finals en tasques de modelatge amb una eina que els proporciona un llenguatge de modelatge visual que permet als usuaris finals seleccionar i personalitzar característiques d'un sistema pervasiu utilitzant conceptes familiars per a ells. Després, aquesta tesi motiva la necessitat d'enriquir processos de DPDM existents per a suportar el desenvolupament d'una nova generació de sistemes programari (per exemple, salut intel¿ligent) que requereixen coneixements especialitzats en una varietat de dominis. Conseqüentment, diferents tipus d'usuaris (per exemple, científics, enginyers i usuaris finals) han de participar activament en la descripció de fragments de models que depenen de la seua experiència utilitzant un llenguatge de modelatge diferent. D'aquesta manera, els usuaris poden col¿laborar per a obtenir una descripció del sistema unificada. En aquest punt, és necessari proporcionar mecanismes que transformen i integren els fragments d'un llenguatge de modelatge a un altre i delimiten quins fragments es descriuen per un usuari diferent. Per a proporcionar açò, la proposta presentada utilitza la gestió de variabilitat de forma nova per a permetre modelatge col.laboratiu seleccionant fragments d'un model del sistema que poden ser descrits utilitzant un llenguatge de modelatge diferent i, la integració d'aqueixos fragments una vegada que hagen sigut descrits. A més, la proposta utilitza mecanismes d'interoperabilitat per a connectar dos llenguatges de modelatge diferents transformant la descripció dels fragments d'una manera no invasiva amb la seua estructura. Per tant, la nostra proposta pot enriquir els models de processos DPDM existents amb fragments de models que han sigut descrits amb un llenguatge diferent i açò, podria fer que els usuaris se senten segurs en adoptar models per a descriure contingut de domini específic i podria ajudar a adoptar processos DPDM. La proposta ha sigut validada en tres casos d'estudi amb diferents nivells de complexitat i dominis: sistemes per a la llar intel¿ligent, sistemes d'informació web i protocols biomecànics. Els resultats han demostrat l'aplicabilitat i viabilitat de la nostra proposta per a involucrar diferents tipus d'usuaris (usuaris finals amb professionals de programari, experts en el domini amb experts en desenvolupament de programari i, metges amb enginyers biomèdics, respectivament) en descripcions de models de processos DPDM existents utilitzant un llenguatge de modelatge diferent.
Pérez Pérez, MF. (2015). Achieving non-intrusive interoperability between models for involving users in modeling tasks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58429
TESIS

Task has been recognized as an influential factor in information seeking behavior. An increasing number of studies are concentrating on the specific characteristics of the task as independent variables to explain associated information-seeking activities. This paper examines the relationships between operational measures of information search behavior, subjectively perceived post-task difficulty and objective task complexity in the context of factual information-seeking tasks on the web. A questiondriven, web-based information-finding study was conducted in a controlled experimental setting. The study participants performed nine search tasks of varying complexity. Subjective task difficulty was found to be correlated with many measures that characterize the searcherâ s activities. Four of those measures, the number of the unique web pages visited, the time spent on each page, the degree of deviation from the optimal path and the degree of the navigation pathâ s linearity, were found to be good predictors of subjective task difficulty. Objective task complexity was found to affect the relative importance of those predictors and to affect subjective assessment of task difficulty.

Técnicas de visualização de informações multidimensionais têm o potencial de auxiliar na análise visual e exploração de grandes conjuntos de dados, através do emprego de mecanismos que buscam tanto representar visualmente os dados quanto permitir ao usuário a interação com estas representações. Neste contexto, diversas técnicas têm sido desenvolvidas, muitas delas sem uma avaliação detalhada e aprofundada tanto de eficiência como de utilidade no suporte às necessidades dos usuários. Contudo, há relativamente pouco tempo começaram a ser publicados trabalhos abordando as diversas questões relacionadas à avaliação de usabilidade de sistemas ou das aplicações que implementam estas técnicas como forma de promover sua eficiente e efetiva utilização. A avaliação de usabilidade de interfaces de sistemas de visualização representa um desafio de pesquisa uma vez que elas apresentam significativas diferenças com relação a outros tipos de interface. Neste sentido, existe uma carência de sistematização (incluindo o uso de métodos e técnicas de avaliação de usabilidade) que explore e considere as características deste tipo de interface de maneira adequada. Esta tese investiga soluções viáveis para o desenvolvimento de uma abordagem sistemática para avaliação de usabilidade de técnicas de visualização de informações multidimensionais e apresenta as seguintes soluções ao problema em estudo: 1) determinação de uma taxonomia de tarefas específica relacionada ao uso de visualizações multidimensionais no processo de análise de dados e 2) adaptação de técnicas e métodos de avaliação de usabilidade, com o objetivo de torná-los mais efetivos ao contexto de sistemas de visualização de informações multidimensionais.
Multidimensional visualization techniques have the potential of supporting the visual analysis and exploration of large datasets, by means of providing visual representations and interaction techniques which allow users to interact with the data through their graphical representation. In this context, several techniques have been developed, most of them being reported without a broad and deep evaluation both regarding their efficiency and utility in supporting users tasks. Few years ago, thus quite recently, several works have been published reporting many issues related to the evaluation of visualization systems and applications, as a means of promoting their efficiency and effective use. In spite of these works, the usability evaluation of visualization systems’ graphical interfaces remains a challenge because of the significant differences between these interfaces and those of other systems. This way, there is a need of finding a systematic approach for such evaluations, including the definition of which usability methods and techniques are best suited for this kind of interfaces. This thesis reports our investigation of viable solutions for the development of a systematic approach for the usability evaluation of multidimensional information visualizations. We have conducted several case studies and experiments with users and have achieved the following contributions: 1) a taxonomy of visualization tasks, that is related to the use of interactive visualization techniques for the exploration and analysis of multidimensional datasets and 2) adaptation of usability evaluation techniques with the goal of making them more effective in the context of multidimensional information visualizations.

This investigation identifies how CAD models of typical automotive body assemblies could be defined to allow a continuous optimisation of the number of iterations required for the final design and the number of variants on the basis of Parametric Associative Design (PAD) and how methodologies for the development of surfaces, parts and assemblies of the automotive body can be represented and structured for a multiple re-use in a collaborative environment of concept phase of a Product Evolution (Formation) Process (PEP). The standardisation of optimised processes and methodologies and the enhanced interaction between all parties involved in product development could lead to improve product quality and reduce development time and hence expenses. The fundamental principles of PAD, the particular methodologies used in automotive body design and the principles of methodical development and design in general are investigated. The role which automotive body engineers play throughout the activities of the PEP is also investigated. The distribution of design work in concept teams of automotive body development and important methodologies for the design of prismatic profile areas is critically analysed. To address the role and distribution of work, 25 group work projects were carried out in cooperation with the automotive industry. Large assemblies of the automotive bodies were developed. The requirements for distributed design work have been identified and improved. The results of the investigation point towards a file based, well structured administration of a concept design, with a zone based approach. The investigation was extended to the process chain of sections, which are used for development of surfaces, parts and assemblies. Important methods were developed, optimised and validated with regard to an update safe re-use of 3D zone based CAD models instead of 2D sections. The thesis presents a thorough description of the research undertaken, details the experimental results and provides a comprehensive analysis of them. Finally it proposes a unique methodology to a zone based approach with a clearly defined process chain of sections for an update-safe re-use of design models.

Research and development on vehicle safety has lately started to direct its focus towards how to actively support the driver and make it easier for her to drive safely through letting Advanced Driver Assistance Systems (ADAS) have effect on how the driver interacts with the vehicle and the surrounding traffic. This requires research on both how the driver and vehicle perform in different situations, in terms of psychology, cognition and individual differences. In addition, physical limitations and requirements of the driver and the vehicle must be taken into account. Therefore scenarios for evaluation of these systems are required. In the area of user-centered design a rather new method, Personas, is being adopted. This thesis tries to explore if the Persona method is a viable tool for creating scenarios for such evaluations. Experiences after completing this work imply that personas indeed is a viable way to include aspects and raise issues concerning individual variability and situational context in ADAS scenarios.

It was analyzed if instructions on a head-worn Augmented Reality display (AR-HWD) are better for manual industrial assembly tasks than instructions on a stationary screen. A prototype was built which consisted of virtual instruction screens for two example assembly tasks. In a comparison study participants performed the tasks with instructions through an AR-HWD and alternatively through a stationary screen. Questionnaires, interviews and observation notes were used to evaluate the task performances and the user experience. The study revealed that the users were excited and enjoyed trying the technology. The perceived usefulness at the current state was diverse, but the users saw a huge potential in AR-HWDs for the future. The task accuracy with instructions on the AR-HWD was equally good as with instructions on the screen. AR-HWDs are found to be a better approach than a stationary screen, but technological limitations need to be overcome and workers need to train using the new technology to make its application efficient.

Stories, themes, concepts and references are organized structurally and purposefully in most books. A person reading a book needs to understand themes and concepts within the context. Schank’s Dynamic Memory theory suggested that building on existing memory structures is essential to cognition and learning. Pirolli and Card emphasized the need to provide people with an independent and improved ability to access and understand information in their information seeking activities. Through a review of users’ reading behaviours and of existing e-Book user interfaces, we found that current e-Book browsers provide minimal support for comprehending the content of large and complex books. Readers of an e-Book need user interfaces that present and relate the organizational and narrative structures, and moreover, reveal the thematic structures. This thesis addresses the problem of providing readers with effective scaffolding of multiple structures of an e-Book in the user interface to support reading for comprehension. Recognising a story or topic as the basic unit in a book, we developed novel story segmentation techniques for discovering narrative segments, and adapted story linking techniques for linking narrative threads in semi-structured linear texts of an e-Book. We then designed an e-Book user interface to present the complex structures of the e-Book, as well as to assist the reader to discover these structures. We designed and developed evaluation methodologies to investigate reading and comprehension in e-Books, in order to assess the effectiveness of this user interface. We designed semi-directed reading tasks using a Story-Theme Map, and a set of corresponding measurements for the answers. We conducted user evaluations with book readers. Participants were asked to read stories, to browse and link related stories, and to identify major themes of stories in an e-Book. This thesis reports the experimental design and results in detail. The results confirmed that the e-Book interface helped readers perform reading tasks more effectively. The most important and interesting finding is that the interface proved to be more helpful to novice readers who had little background knowledge of the book. In addition, each component that supported the user interface was evaluated separately in a laboratory setting and, these results too are reported in the thesis.

The first step in developing or updating a licensure or certification examination is to conduct a job or task analysis. Following completion of the job analysis, a survey validation study is performed to validate the results of the job analysis and to obtain task ratings so that an examination blueprint may be created. Psychometricians and job analysts have spent years arguing over the choice of scales that should be used to evaluate job tasks, as well as how those scales should be combined to create an examination blueprint. The purpose of this study was to determine the relationship between individual and composite rating scales, examine how that relationship varied across industries, sample sizes, task presentation order, and number of tasks rated, and evaluate whether examination blueprint weightings would differ based on the choice of scales or composites of scales used. Findings from this study should be used to guide psychometricians and job analysts in their choice of rating scales, choice of composites of rating scales, and how to create examination blueprints based upon individual and/or composite rating scales. A secondary data analysis was performed to help answer some of these questions. As part of the secondary data analysis, data from 20 survey validation studies performed during a five year period were analyzed. Correlations were computed between 29 pairings of individual and composite rating scales to see if there were redundancies in task ratings. Meta-analytic techniques were used to evaluate the relationship between each pairing of rating scales and to determine if the relationship between pairings of rating scales was impacted by several factors. Lastly, sample examination blueprints were created from several individual and composite rating scales to determine if the rating scales that were used to create the examination blueprints would ultimately impact the weighting of the examination blueprint. The results of this study suggest that there is a high degree of redundancy between certain pairs of scales (i.e., the Importance and Criticality rating scale are highly related), and a somewhat lower degree of redundancy between other rating scales; but that the same relationship between rating scales is observed across many variables, including the industry for which the job analysis was being performed. The results also suggest the choice of rating scales used to create examination blueprints does not have a large effect on the finalized examination blueprint. This finding is especially true if a composite rating scale is used to create the weighting on the examination blueprint.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Ubiquitous computing foresees the support to human activities in the most possible integrated environment known by the professional. On this perspective, a major area of its application is the Health System as the health of the future provides the use of ubiquitous computing as a way to automate and optimize the clinical activities. Addressing the problem of rejection of computer systems in health due to the remoteness of the way clinicians perform their tasks, the project "ClinicSpace" proposes a prototype of a tool that enables clinicians to customize and better manage their daily tasks. One of the big challenges is how to model human activities in computer systems, respecting the way that each individual performs them. This way, the contribution of this work is to propose a modeling of the main tasks performed in the clinical hospital settings by clinical professionals with the way that each individual performs the work. Once created the task, the medical professionals can reuse them for the definition and creation of other tasks they may judge necessary. An architecture manages the tasks in the most automatic way possible to undermine the control that the owner must maintain to the environment. Thus, it is expected to reduce the degree of rejection found in computerized systems of hospitals and clinics. The interface developed uses mechanisms provided by the End-user programming to facilitate the use of the clinical professional and Task-driven Computing. Case studies were simulated to demonstrate the feasibility of the proposal. Field tests may only be made after the release of the prototype of the architecture of the management and execution of tasks; however, this work is outside the scope of this dissertation.
A Computação Ubíqua prevê o suporte às atividades humanas da forma mais integrada possível ao ambiente conhecido pelo profissional. Nessa perspectiva, uma das grandes áreas de aplicação é a Saúde, já que o Sistema de Saúde do futuro prevê o uso da Computação Ubíqua como forma de otimizar e automatizar as atividades clínicas. Focando o problema de rejeição dos sistemas computacionais na Saúde devido ao distanciamento destes da forma como os clínicos executam suas tarefas, o projeto ClinicSpace propõe a prototipação de uma ferramenta que permita aos clínicos a personalização e gerenciamento de suas tarefas diárias. Um dos grandes desafios enfrentados é como modelar atividades humanas em sistemas computacionais, respeitando a forma individualizada com que cada pessoa as realiza. Nesse sentido, a contribuição desse trabalho é a proposta de uma ferramenta-piloto que permite ao profissional programar e compor suas tarefas, a partir de uma modelagem das principais tarefas clínicas executadas nos ambientes hospitalares por profissionais clínicos, respeitando a forma individual que cada profissional as realiza. Uma vez criadas as tarefas, os profissionais clínicos podem reutilizá-las para a definição e reuso na criação de outras tarefas que julgarem necessário. Uma arquitetura gerencia a execução das tarefas da forma mais automática possível para não comprometer o controle que o profissional deve manter sobre o ambiente. Assim, espera-se reduzir o grau de rejeição encontrado nos sistemas informatizados dos hospitais e clínicas. A interface de programação de tarefas pelo profissional desenvolvida utiliza mecanismos providos pela Programação Orientada ao Usuário-Final com o objetivo de facilitar a utilização do sistema pelo profissional clínico e pela Computação Orientada a Atividades. Estudos de casos foram simulados para demonstrar a viabilidade da proposta. Testes de campo somente poderão ser realizados após a disponibilização do protótipo da arquitetura de gerenciamento e execução das tarefas, porém, esse trabalho está fora do escopo dessa dissertação.

Force est de constater que composer des applications existantes afin d'en réutiliser tout ou une partie est une tâche complexe. Pourtant avec l'apparition quotidienne d'applications, les éditeurs d'applications ont de plus en plus besoin d'effectuer de telles compositions pour répondre à la demande croissante des utilisateurs. Les travaux existants ne traitent généralement que d'un seul point de vue : celui du "Noyau Fonctionnel" dans le domaine du Génie Logiciel, celui des Tâches" ou celui de l'"Interface Graphique" dans le domaine des Interactions Homme-Machine (IHM). Cette thèse propose une nouvelle approche basée sur un modèle d'application complet (fonctionnel, tâche et interface graphique). Elle permet à un utilisateur de naviguer entre ces différents modèles pour sélectionner des ensembles cohérents pouvant être composé par substitution. Une implémentation de cette approche a permis d'effectuer des tests utilisateurs confortant les bienfaits d'une modélisation complète.

Datalager används för att ge företag en samlad bild av sin verksamhet, en bild som byggs upp av analytikers statistiska beräkningar och modeller. Analytiker arbetar i datalager med hjälp av olika analysverktyg, och begränsas av dessa verktygs möjligheter att ge en förståelse av datalagrets uppbyggnad och funktion, och av möjligheterna att hitta rätt analysdata. Arbetet med att hitta och analysera data är en iterativ problemlösningsprocess för att få fram det önskade resultatet.

Visualiseringar kan fungera som ett verktyg i arbetet och stödja användares beslutsfattande. Denna kvalitativa fallstudie syftar till att undersöka hur visualisering kan användas som ett stöd för marknads- och kreditanalytikers datalagerarbete. Studien använde användarcentrerade metoder för att undersöka analytikers arbete i ett datalager. Femton kunskapsuppgifter identifierades som mål för visualiseringsstöd i analytikers datalagerarbete. Ett analysorienterat och ett systemorienterat strukturförslag för visualiseringar värderades med dessa kunskapsuppgifter som viktade mål.

Av kunskapsuppgifterna är den viktigaste att koppla analysuppgifter till systemstruktur. Det kräver att visualiseringsstödet erbjuder en analysorienterad struktur initialt och blir alltmer systemorienterat i takt med att den intressanta informationsmängden definieras. Användarcentrerade metoder användes för att identifiera kunskapsuppgifter. Studien visar att dessa kunskapsuppgifter kan användas som designmål för värdering av visualiseringsstöd.

Purpose: We explored performance across time in a word-learning task for second grade children. Method: Our participants included 107 children: 48 typically developing monolinguals, 30 typically developing bilinguals, 14 dyslexic only, four with language impairment, and 11 with comorbid dyslexia and language impairment. After meeting inclusionary criteria, children participated in six session of pirate-themed games. This study focused on one aspect of the word-learning game, the phonological-visual linking task. We compared participants' average scores across each session to explore the possibilities of distinctive patterns of learning, perseverance, or boredom shown across time. Results: Cluster analysis revealed five different clusters of performance. The largest cluster, Group 5, contained the largest percentage of children from each category, except the language impairment category. Group 5 performed the best and showed improvement over time. Group 1 was the worst group, starting with fair accuracy and gradually becoming less accurate over time. Group 1 consisted of a fairly even percentage of children from each category. Conclusion: Impaired children and typically developing children are both capable of increased learning across time in this phonological-visual linking task, and children with impairments are not at significantly greater risk than peers for boredom effects.

With the significant improvement in IoT technology and smart devices, data collection and distributed computation have led a foundation for Mobile crowd-sensing (MCS). MCS utilizes the capabilities of embedded sensors in smart devices for gathering data. MCS benefits both data provider (participant/user), and data requester, i.e. data providers via incentives/rewards, data requesters by delivering required data. Apart from the benefits gained through acquiring data, confronting challenges such as participant privacy, data trustworthiness, malicious attacks (from illegitimate users) need to be addressed to build robust and reliable data solicitation. In addition to that, it is necessary to consider user motivation and user preference, comfort during its engagement in crowd-sensing. User preferences/constraints can be due to privacy concerns in terms of location, the sensitivity of data or energy usage and many more. With this in mind, the main contributions of the thesis can be listed as follows. 1) We design user selective trustworthy data acquisition frameworks. We introduce a variety of user selection criteria to form participant communities based on participants reliability and income. To evaluate the trustworthiness of our selective reputation-based data acquisition, we consider malicious users in the environment and calculate the total rewards given to malicious users. Simulations results show that community formation based on the acquired income of participants ended up with a substantial loss to the cloud platform as well as participants. Contrary to that, reputation-based community formation has shown nearly equal platform utility (profit), negligible loss of user utility compared to benchmark Non-selective data acquisition with 7% malicious probability. 2) Moreover, we attempt to enable users to modify (allow/deny access to) their builtin sensor set according to their comfort levels. We formulate three comfort levels high (only allow access to sensors that would not directly reveal personal identity such as accelerometer, light sensor, etc.), moderate (obstruct access to sensitive data, e.g. camera), zero comfort (allow access to all users). We introduce Static modification, where users pre-arrange their sensor set before the start of data collection. Our feasibility study shows that pre-arrangement of the sensor set favours user comfort, user utility at the cost of loss in platform utility and performs better than selective reputation-based recruitment for the considered settings. 3) We apply Adaptive sensor modification on top of pre-arrangement of sensor set through which participants are authorized to re-arrange their sensor availability based on reliability scores. Simulation results show that the Adaptive comfort-aware approach performed better than static in terms of platform utility and achieved comparatively better user comfort with reasonable loss in user utility.

En raison du grand succès des réseaux sans _l et des appareils portatifs, le paradigme de l'informatique pervasive est devenu une réalité. L'un des plus di_ciles objectifs à atteindre dans de tels environnements est de permettre à l'utilisateur d'exécuter une tâche en composant à la volée, les services et les ressources de l'environnement. Cela implique la correspondance et la sélection automatique de services à travers divers dispositifs de l'environnement pervasif. Les approches existantes considèrent souvent seulement les aspects fonctionnels des services et ne prennent pas en compte diff érents aspects non-fonctionnels tels que les préférences utilisateur, les capacités des dispositifs en termes matériels et logiciels, et l'hétérogénéité du réseau de ces dispositifs. Nous présentons une approche pour la sélection dynamique des composants et des dispositifs dans un environnement pervasif en considérant simultanément tous les aspects précédemment mentionnés. Premièrement, nous proposons une modélisation abstraite et concrète de l'application, des capacités des terminaux et des ressources, des préférences des utilisateurs, ainsi que la modélisation de la plate-forme réseau sous-jacente. Les capacit és des dispositifs sont représentées par notre extension du modèle CC/PP et les préférences des utilisateurs en utilisant notre extension du modèle CP-Net. Nous mod- élisons sous forme d'un graphe la tâche de l'utilisateur et des services réseau sous-jacent, ainsi que les exigences des services, des préférences utilisateur et les capacités des dispositifs. L'hétérogénéité des protocoles de communication est également considérée dans les graphes. Les aspects algorithmiques ont été traités en fournissant des algorithmes pour la correspondance entre les services et les composants, pour la projection des applications sur la plate-forme de composants existants et pour l'évaluation des préférences utilisateurs. Pour la description de la composition de l'application nous proposons un modèle SCA étendu. Partant d'une composition abstraite de services, nous arrivons à réaliser une composition concrète de l'application distribuée à travers les dispositifs existants. Si pendant l'exécution un nouveau meilleur dispositif apparaît, l'application est recomposée en tenant compte des nouveaux composants. Cela permet de réaliser la continuité de la session d'un dispositif vers un autre. Une mise en oeuvre d'un prototype et son évaluation sont également fournis
Due to the large success of wireless networks and portable devices, the pervasive computing paradigm is becoming a reality. One of the most challenging objectives to be achieved in pervasive computing environments is to allow a user to perform a task by composing on the _y the environment's service and resource components. This involves automatic matching and selection of services across various devices in the pervasive environment. Existing approaches mostly consider only functional aspects for service and component matching and do not consider various non-functional aspects such as user preferences, device capabilities in terms of software and hardware, and network heterogeneity of devices. We present an approach for dynamic selection of components and devices in a pervasive environments considering all the aforementioned aspects simultaneously. First, we provide a modeling of abstract and concrete application, device capabilities and resources, user preferences as well as modeling of the underlying connected platform. Device capabilities are represented by our extended CC/PP model and user preferences using our extended CP-net model. We model both the user task and the underlying network services, along with service requirements, user preferences and device capabilities, as graphs. The heterogeneity of communication protocols is also considered in the graph. The algorithmic aspects have been treated by providing algorithms for service and component matching, application mapping on network platform and user preference evaluation. For description of application composition extended SCA model is used. Departing from an abstract composition, we arrive on achieving a concrete application composition which may be distributed across more than one device. If during the application execution a new, better device appears, the application is recomposed to replace the existing components by the newer ones. This also implies the continuity of session from one device to another. A prototype implementation and its evaluation are also provided

Thesis (Ph. D.) -- University of Maryland, College Park, 2007.
Thesis research directed by: Library & Information Services. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

This thesis describes a series of eight experiments that examined working memory involvement and strategy use during mental comparison tasks. The main conclusions drawn from the results of the eight experiments are as follows: Firstly, the evidence suggests that the spatial 'inner scribe' component of working memory (Logie, 1995) is involved during mental comparisons based on relative size. This conclusion is based on the finding that concurrent spatial tapping selectively interferes with subjects' performance on mentally comparing the angles between the hands of imaged analogue clocks (Experiment 3), the comparison of the size of a shaded section of a circle with one presented previously (Experiment 4), and the comparison of objects' relative sizes based on information stored in long-term memory (Experiments 7 and 8). It is argued in the general discussion chapter of this thesis that the functions attributed to the 'inner scribe' working memory system are comparable with the collection of spatial subsystems proposed by Kosslyn in his computational model of imagery (Kosslyn, 1980; 1991; 1994). Secondly, the results of this thesis suggest that during mental comparison tasks the majority of subjects combine the generation of visual images with additional verbal strategies. This finding is in contrast to previous literature (e.g., Paivio, 1975; 1978b), which has tended to assume that subjects' performance of mental comparisons is dependent purely on the utilisation of a visual imagery strategy. Post-task strategy questionnaires administered in Experiments 4 to 8 revealed that consistently around 25% of subjects did not report being aware of relying to any great extent on visual images while making the mental comparisons. In Experiments 2 and 3 it was also demonstrated that the adoption by subjects of a combined imagery/verbal strategy was less effective for comparing mental clocks than the utilisation of a pure imagery strategy, and moreover that reliance on verbal strategies during the mental clocks task could be disrupted by concurrent relevant speech or oral random generation. Conversely, in Experiment 4 it was demonstrated that when a variant of the clock task termed the 'wedge task' was used as a primary task, the adoption of a pure verbal strategy corresponded to the absence of any significant effect of angular separation on response times, in contrast to those subjects who did report using visual images as a basis for making the comparison. In addition, the utilisation of a pure verbal strategy was shown to be more effective than an imagery strategy for the smaller wedge comparisons, with the opposite pattern of results occurring with larger wedge comparisons. Finally, in the general discussion chapter of this thesis an attempt is made to clarify the relationship between the subsystems of working memory and the generation and manipulation of visual images. It is argued that the computational model of imagery developed by Kosslyn and the current two-component model of visuo-spatial working memory are not directly comparable. Instead, the subsystems of VSWM are deemed to be functionally separate from the visual buffer, though they are assigned a vital role during cognitive operations such as image transformations, and during the transference of information from long-term memory into the visual buffer. Finally, an attempt is made to integrate aspects of both working memory and imagery theories, particularly in the areas of visual rehearsal and the maintenance of images within the visual buffer.

Previous research has shown that most antihistamines have sedative effects and can lead to deterioration of psychomotor performance. The objective of this research was to determine if two antihistamines (diphenhydramine and astemizole) administered at a therapeutic dose level will affect a subject's visual search capabilities. The results of this research indicate that astemizole did not significantly decrement a subject’s ability to visually search as compared to the performance of that same subject after ingesting a placebo. Diphenhydramine produced significantly poorer visual search results than did astemizole.
Master of Science

Two previous studies performed at Virginia Tech have shown that it is feasible to detect drowsy drivers using driving performance and physiological measures. Therefore, assuming that drowsiness can be detected, it becomes important to develop methods (countermeasures) by which drivers can regain and maintain alertness. The current study was thus undertaken in an attempt to evaluate three subsidiary tasks which differed only in regard to input modality (auditory, tactual, or visual) in terms of: 1) the degree to which they aided the driver by maintaining or restoring alertness; and 2) the degree to which the responses to these tasks could be used to detect drowsiness. Subjective measures of drowsiness were also obtained to provide an additional source of verification of level of drowsiness. To accomplish these objectives, a total of 12 male and female driver-subjects drove a moving-base simulator continuously from 12:30 a.m. to 3:00 a.m. During this time, the subjects performed each of the subsidiary tasks for a 30-minute period; they also drove for a 30-minute period during which no subsidiary task was performed. During the simulated, nighttime, highway driving scenario, 20 driving performance, behavioral, and physiological measures were collected for each 3-minute driving interval, along with 5 subsidiary task measures and subjective alertness ratings. The experimental results indicated that none of the three subsidiary tasks provided an effective means of maintaining driver alertness. However, the results of a second series of discriminant analyses did indicate that driver impairment due to drowsiness could be reliably detected with linear combinations of subsidiary task and driving measures. In fact, promising discriminant models for the auditory and visual tasks were identified which employed a subsidiary task response measure of the number of correct responses to the subsidiary task during each 6-minute driving interval as well as a physiological measure of the subject's heart rate variance; these models showed overall classification error percentages as low as 3% and 8%. Finally, the analyses of the subjective alertness ratings indicated that subjects' ratings were not significantly affected by either the type of subsidiary task performed or time-on-task.
Ph. D.

The overarching aim of this thesis was to enhance the prediction of physical activity energy expenditure (PAEE) in military personnel; specifically, improving accuracy and minimising obtrusiveness. The first experimental chapter provided a thorough assessment of the reliability and validity of the 3DNX accelerometer. Within unit reliability (CVintra) physical activity counts (PAC) was 0.0-8.9% in all axes in a mechanical setting. Between unit reliability (CVinter) did not exceed 4.5%.The relationship between PAC and acceleration was r2 = 0.99 and standard error of the estimate (SEE) of 6 counts∙5s-1. During treadmill exercise, the relationship between and PAC was linear (walking, r2 =0.65, SEE = 1.42 ml·kg-1·min-1; running, r2 =0.62, SEE = 3.63 ml·kg-1·min-1). 3DNX PAC output was valid and reliable when subjected to a physiologically relevant range of mechanically generated accelerations and yielded a linear relationship with during treadmill walking and running. Chapter 7 investigated the effect of anatomical placement on PAC in order to find the most suitable wear location. Hip and back placements returned similar reliability (CVintra = 3.0% and 2.8% respectively). Hip PAC were higher (p < 0.01) for walking with no differences observed for running. Indices of adiposity were related to hip PAC. Regression analysis revealed hip and back PAC as significant predictors of . Back PAC was the least variable placement. Supraspinale skinfold thickness explained 15% additional variance in to PAC and reduced SEE. In Chapter 8, three available devices were compared to doubly labelled water (DLW) for the prediction of free living PAEE using a user-oriented approach. All devices underestimated PAEE. Actiheart-derived PAEE was not different from DLW. However, the wide absolute limits of agreement (LoA) indicated large individual error which was attributed to the use of group rather than individual calibration. 3DNX and GT3X PAEE predictions were different from DLW however LoA were narrower indicating the possibility of applying a correction factor in future. Chapter 9 was an amalgamation of ten independent cohorts in an attempt to produce a military-specific multivariate model for the prediction of energy expenditure (EE). Stringent data reduction techniques were applied to a highly compliant dataset. Allometric models showed PAC, height and body mass were related to total energy expenditure (TEE) (p < 0.01). For models predicting TEE, PAC explained 4 % of the variance. For models predicting PAEE, PAC accounted for 6 % of the variance. The small amount of variance explained by PAC was likely due to the inability of accelerometers to detect EE as a result of day-to-day military activities such as load carriage. Such small portions of explained variance indicate that traditional accelerometry techniques are inadequate for use in military populations. In Chapter 10, an alternative approach to characterising military-specific activities was explored due to the minor contribution of PAC to PAEE prediction in Chapter 9. Accelerometer raw signal (100 Hz) was used to develop a classification model which aimed to discriminate load carriage (LC) from unloaded ambulation during an occupationally relevant protocol (2-hours, 6.4km∙hr-1, 25kg load). Fast Fourier transformation showed differences in the frequency distribution of the signal between conditions; caused by differences in gait parameters. Load carriage was detected in 97.2% of 1-minute samples with reduced classification accuracy during the last 30 minutes. Fatigue was suggested as a cause of misclassification; indicated by an upwards drift in and RPE across time. In conclusion, accelerometer PAC is a weak contributor to the prediction of energy expenditure in military populations. Accuracy could be improved by detection of load bearing activities which is feasible given the advancement in technology and analysis techniques. New technologies such as optical interferometrics could be integrated into existing military equipment to detect heartbeat and respiration; providing data regarding the physiological strain of training and operations.

This thesis investigates the effects of strategy training on ESL learners' strategy use and performance on oral communication tasks. Research into the teaching and learning of speaking in the ESL context is relatively neglected and strategy training is unheard of in very many L2 oral classrooms. A review of strategy research pertaining to the speaking skill has identified unresolved issues, leaving many unanswered questions. To address these issues, this study has adopted a quasi-experimental design and an interventionist study has been implemented in the junior ESL classroom in Hong Kong. The study has identified two major categories of strategies (i. e. direct and indirect) for learners' use in group discussion tasks. Three intact groups were involved in the intervention: one received training in the use of direct strategies, one in indirect strategies, and one had no strategy instruction. A multi-method approach (i. e. task ratings, questionnaires, observations and stimulated recall interviews) has been used to assess the impact of the intervention on students' strategy use and task performance. The findings show that that it may be useful to teach ESL students in the use of direct and indirect strategies for oral communications tasks. Direct strategy use may be related to language improvement whereas indirect strategy use may be related to task effectiveness and language improvement. It may be desirable to help low-proficiency students to develop strategic competence to compensate for their lack of linguistic competence. Last but not least, it may be desirable to adopt a systematic, eclectic approach to assessing the impact of strategy training and to incorporate the stimulated recall methodology to the teaching and research of the speaking skill as a unique avenue to students' thoughts and learning processes.