Dissertations / Theses on the topic 'Contextual search'

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.
Includes bibliographical references (p. 76-77).
This thesis describes the design and development of an application that uses information relevant to the context of a web search for the purpose of improving the search results obtained using standard search engines. The representation of the contextual information is based on a Vector Space Model and is obtained from a set of documents that have been identified as relevant to the context of the search. Two algorithms have been developed for using this contextual representation to re-rank the search results obtained using search engines. In the first algorithm, re-ranking is done based on a comparison of every search result with all the contextual documents. In the second algorithm, only a subset of the contextual documents that relate to the search query is used to measure the relevance of the search results. This subset is identified by mapping the search query onto the Vector Space representation of the contextual documents. A software application was developed using the .NET framework with C# as the implementation language. The software has functionality to enable users to identify contextual documents and perform searches either using a standard search engine or using the above-mentioned algorithms. The software implementation details, and preliminary results regarding the efficiency of the proposed algorithms have been presented.
by Hariharan Lakshmanan.
S.M.

Contextual information retrieval (CIR) is a critical technique for today’s search engines in terms of facilitating queries and returning relevant information. Despite its importance, little progress has been made in its application, due to the difficulty of capturing and representing contextual information about users. This thesis details the development and evaluation of the contextual SERL search, designed to tackle some of the challenges associated with CIR from the World Wide Web. The contextual SERL search utilises a rich contextual model that exploits implicit and explicit data to modify queries to more accurately reflect the user’s interests as well as to continually build the user’s contextual profile and a shared contextual knowledge base. These profiles are used to filter results from a standard search engine to improve the relevance of the pages displayed to the user. The contextual SERL search has been tested in an observational study that has captured both qualitative and quantitative data about the ability of the framework to improve the user’s web search experience. A total of 30 subjects, with different levels of search experience, participated in the observational study experiment. The results demonstrate that when the contextual profile and the shared contextual knowledge base are used, the contextual SERL search improves search effectiveness, efficiency and subjective satisfaction. The effectiveness improves as subjects have actually entered fewer queries to reach the target information in comparison to the contemporary search engine. In the case of a particularly complex search task, the efficiency improves as subjects have browsed fewer hits, visited fewer URLs, made fewer clicks and have taken less time to reach the target information when compared to the contemporary search engine. Finally, subjects have expressed a higher degree of satisfaction on the quality of contextual support when using the shared contextual knowledge base in comparison to using their contextual profile. These results suggest that integration of a user’s contextual factors and information seeking behaviours are very important for successful development of the CIR framework. It is believed that this framework and other similar projects will help provide the basis for the next generation of contextual information retrieval from the Web.

The contextual cueing effect was initially thought to be the product of memory guiding attention to the target location. However, the steep search slopes obtained in contextual cueing indicate an absence of attentional guidance. We hypothesized that crowding could be obscuring the presence of attentional guidance and investigated this possibility in 2 experiments. Crowding was manipulated by varying the density of items in the local target region in a contextual cueing task. We observed a significant reduction in search slopes between the novel and repeated conditions when crowding was reduced. Enhancing crowding eliminated the contextual cueing effect. These findings suggest that increased crowding at larger set sizes attenuates the memory-based attentional guidance in contextual cueing thereby producing steep search slopes.

My examination project during spring 2011 has been carried out in collaboration with DuoBad, a bathroom furniture company situated in Alsterbro, Småland. Their focus is to develop, manufacture and market bathroom furnitures with genuine craftsmanship. Through their partnership with some of the most influential manufacturers of quality bathroom products they can create an entirely new room to enjoy.I initiated the collaboration with DuoBad for the examination project and have not started from a specific task, but together with the company I have been focused on adding new thinking regarding storage in bathroom furniture.The goal with the project has been to, together with DuoBad, develop a conceptual set of bathroom furniture that provides new ways of storing.The project was a close collaboration with users where experience gained through contextual interviews became the main source of inspiration.The result of the project is a bathroom furniture serie called Mill. The name comes from the manufacturing technique of milling, which is the identifying form language of the product.

In Zambia, it is true to say that people are politically free but materially still very poor, 49 years after independence which was attained in 1964. Many people lie below poverty datum-line and those that are, most hit, are the people living in rural areas. Many people are flocking from the rural areas to cities, leaving the old people, women and children in rural areas and in poverty. The levels of poverty in Zambia have reached a crisis, that even the president of Zambia, His Excellence Mr. Michael Chilufya Sata, acknowledged this fact during his parliamentary address to the second session of the 11th National assembly broadcast live on Zambia National broadcasting Network in September 2012. The church is challenged by conditions under which the rural dwellers find themselves in. As a church, our political liberation is to be transformed and driven by the will to restructuring and healing our society; thus ultimately developing those individuals who are suffering in the rural areas of the country. In Zambia, the church should accept that the missionaries who brought the gospel from western countries worked very well in the area of community development. The missionaries’ work and their care for the poor should inspire the churches today to be willing to help the poor rural people to be transformed. The good thing the United Church of Zambia could learn from the early missionaries is that the Christian church needs to be committed and involved in the plight of the poor. The church cannot ignore the socio – economic issues that affect rural poor communities. The United Church of Zambia should be transformed and made to understand that human liberation is not possible, if the political and economic issues are not equally addressed, a human being is not only the soul but also, consist of body and mind. The Christian church must bring a holistic ministry to the suffering people. The church; especially the United Church of Zambia, should understand that economic freedom is a reality which cannot be separated from people’s daily life. The church should learn to listen and act as ‘a midwife’ and a place of safety. She must be willing to suffer with the poor, for the sake of the poor. While the church is committed to development issues, let it also not lose sight of spiritual issues. Therefore, the church leadership should serve as a role model in human and community development. The Christian church should use the gospel to change the mind-set of the rural poor in order to help them transform their living standards.
Thesis (PhD)--University of Pretoria, 2013.
gm2014
Practical Theology
unrestricted

Face à la surcharge informationnelle inhérente à la complexité du monde visuel, pour pallier la limitation de ses capacités de traitement et ajuster au mieux son comportement, l’être humain est capable d’apprendre et d’exploiter des régularités présentes dans son environnement visuel. S’il est complexe, le monde visuel n’en est effectivement pas moins hautement structuré et redondant, le contexte dans lequel s’inscrivent les objets constituant dès lors une source de prédictibilité profitable aux observateur·rice·s. Depuis une vingtaine d’années, le paradigme de Contextual Cueing (CC) offre un outil expérimental pour étudier, en laboratoire, comment il est ainsi possible d’apprendre des régularités spatiales existant dans la localisation relative de différents objets, pour faciliter les comportements de recherche visuelle. Le CC alimentant une littérature particulièrement abondante et prolifique, la première partie de cette thèse fait état de l’ensemble des travaux préexistants sur le paradigme. Au travers de cette revue de questions, sont principalement discutées la nature implicite du phénomène, la caractérisation des connaissances acquises et de leur effet facilitateur, ainsi que la transposabilité et la généralisation du CC spatial à d’autres régularités ou environnements. Dans une seconde partie, nous présentons trois études expérimentales menées à partir de ce paradigme. La première d’entre elles montre que dans des scènes naturelles, l’acquisition de connaissances implicites tend à précéder l’exploitation consciente des régularités classiquement attachée au CC dans ce type d’environnement. Dans des contextes artificiels et abstraits (i.e., configurations de lettres), si le CC ne paraît pas avant tout dépendre de la bonne mise en œuvre de processus explicites et conscients, notre deuxième étude rapporte que son intégrité est menacée au cours du vieillissement normal. Enfin, notre troisième étude explore les possibilités d’apprentissage en situation d’expositions très brèves aux régularités (i.e., 50ms), et suggère que ces dernières peuvent effectivement être extraites et exploitées alors même que les environnements de recherche ne sont pas (physiquement) disponibles suffisamment longtemps pour permettre à la recherche d’être complétée
While deeply complex, the visual world is highly structured and redundant. Through experience, human beings can thus learn regularities present in the visual world, and exploit them to deal with information overload and facilitate behaviors. For the past twenty years, the Contextual Cueing (CC) paradigm has provided an experimental tool to study, in the laboratory, how spatial regularities can be learned to expedite visual search. The first part of this dissertation reviews the existing literature related to this paradigm. It mainly discusses the implicit nature of CC, the characterization of the acquired knowledge and its facilitating effect, as well as the generalization of spatial CC to other regularities and environments. In a second part, three experimental studies using the CC paradigm are presented. The first one shows that, in natural scenes, the acquisition of implicit knowledge tends to precede the conscious exploitation of regularities that classically accompanies CC in this type of environment. In artificial scenes (i.e., letter configurations), even if CC does not seem to primarily depend on the proper implementation of explicit and conscious processes, our second study reports that its integrity is threatened during normal ageing. Finally, our third study investigates whether CC can emerge from very brief exposures of regularities (i.e., 50ms), and suggests that regularities can actually be extracted and exploited even though search displays are not (physically) available long enough to complete the search

In this thesis, we will explore direct and indirect measures of learning in a visual search task commonly called contextual cueing. In the first part, we present a review of the scientific literature on contextual cueing, in order to give the readers of this thesis a better general idea of existing evidence and open questions within this relatively new research field. The aims of our own experimental studies presented in the succeeding chapters are the following ones: (1) to replicate and extend the findings described in the various papers by Marvin Chun and various colleagues on contextual cueing of visual attention; (2) to explore the nature of memory representations underlying the observed learning effects, especially whether learning is actually implicit and whether memory representations are distinctive, episodic and instance-based or rather distributed, continuous and graded; (3) to extend the study of contextual cueing to more realistic visual stimuli, in order to test its robustness across various situations and validate its adaptive value in ecologically sound conditions;

and (4) to investigate whether such knowledge about the association between visual contexts and “meaningful” locations can be (automatically) transferred to other tasks, namely a change detection task.

In a first series of four experiments, we tried to replicate the documented contextual cueing effect using a wide range of various direct measures of learning (tasks that are supposed to be related to explicit knowledge) and we systematically varied the distinctiveness of context configurations to study its effect on both direct and indirect measures of learning.

We also ran a series of neural network simulations (briefly described in the general discussion of this thesis), based on a very simple association-learning mechanism, that not only account for the observed contextual cueing effect, but also yield rather specific predictions about future experimental data: contextual cueing effects should also be observed when repetitions of context configurations are not perfect, i.e. the networks were able to react to slightly distorted versions of repeating contexts in a similar way than they did to completely identical contexts. Human participants, we conjectured, should therefore (if the simple connectionist model captures some relevant aspects of the contextual cueing effect) become faster at detecting targets surrounded by context configurations that are only partially identical from trial to trial compared to those trials where the context configurations were randomly generated. These predictions were tested in a second series of experiments using pseudo-repeated context configurations, where some distractor items were either displaced from trial to trial or their orientation changed, while conserving their global layout.

In a third series of experiments, we used more realistic images of natural landscapes as background contexts to establish the robustness of the contextual cueing effect as well as its ecological relevance claimed by Chun and colleagues. We furthermore added a second task to these experiments to study whether the acquired knowledge about the background-target location associations would (automatically) transfer to another visual search task, namely a change detection task. If participants have learned that certain locations of the repeated images are “important”, since they contain the target item to look for, then changes occurring at those specific locations should lead to less “change blindness” than changes occurring at other irrelevant locations. We used two different types of instructions to introduce this second task after the visual search task, where we either stressed the link between the two tasks, i.e. telling them that remembering the “important” locations for each image could be used to find the changes faster, or we simply told them to perform the second task without any reference to the first one.

We will close this thesis with a general discussion, combining findings based on our review of the existing research literature and findings based on our own experimental explorations of the contextual cueing effect. By this we will discuss the implications of our empirical studies for the scientific investigation of contextual cueing and implicit learning, in terms of theoretical, empirical and methodological issues.
Doctorat en sciences psychologiques
info:eu-repo/semantics/nonPublished

This diploma work deals with specific business concept and with possibilities of a company promotion on the Internet. The theoretical segment contains a survey of the Internet business models and a synopsis of current individual forms of promotion used on the Internet. There are described advantages and disadvantages of banner advertising, contextual advertising, email marketing, search engine marketing (SEM), social networks and affiliate marketing. The final part of theoretical section of the thesis is dedicated to the possibilities of propagation efficiency measurements. Practical part of the diploma work introduces author's own business concept and its business model. The description of specific methods of propagation realized in congruence with the noted business concept follows.

This work deals with internet advertising. Describes the basic characteristics of Internet marketing, survey errors that nascent entrepreneurs engage in formulating goals. Discusses the different types of advertising on the Internet usable in terms of functionality, payment options. It also offers an overview of advertising systems that provide these types of ads. In connection with advertising, the work deals with the problem of blocking. On show are the best known systems that block ads, but also ways to bypass such systems. The aim is to give people who want to invest money into advertising, relevant information about our services and help them choose the right type of promotion for your website. According to predefined criteria to verify the suitability of advertising and advertising system on the guesthouse accommodation in Spindleruv Mlyn. The performance is selected advertising system, its functions, a detailed procedure for creating the campaign and its optimization. The results presented show that the ad was chosen correctly. In addition, there are suggested ways to improve an existing campaign.

博士
國立臺灣大學
資訊網路與多媒體研究所
105
With the prevalence of capture devices, people are used to share their images and videos on the social media (e.g., Flickr and Facebook). To provide relevant information (e.g., reviews, landmark names, products) for these uploaded media, the need for effective and efficient visual search (e.g., image retrieval, mobile visual search, product search) is emerging. It enables plenty of applications such as recommendation, annotation, and advertisement. The state-of-the-art approaches (visual features) usually suffer from low recall rates because small changes in lighting conditions, viewpoints, or occlusions could degrade the performance significantly. We observe that enormous media collections are along with rich contextual cues such as tags, geo-locations, descriptions, and time. Hence, we propose to exploit different contextual information with the state-of-the-art visual features for solving the above challenges, and are able to improve the retrieval accuracy and provide diverse search results.

abstract: Previous research has shown that people can implicitly learn repeated visual contexts and use this information when locating relevant items. For example, when people are presented with repeated spatial configurations of distractor items or distractor identities in visual search, they become faster to find target stimuli in these repeated contexts over time (Chun and Jiang, 1998; 1999). Given that people learn these repeated distractor configurations and identities, might they also implicitly encode semantic information about distractors, if this information is predictive of the target location? We investigated this question with a series of visual search experiments using real-world stimuli within a contextual cueing paradigm (Chun and Jiang, 1998). Specifically, we tested whether participants could learn, through experience, that the target images they are searching for are always located near specific categories of distractors, such as food items or animals. We also varied the spatial consistency of target locations, in order to rule out implicit learning of repeated target locations. Results suggest that participants implicitly learned the target-predictive categories of distractors and used this information during search, although these results failed to reach significance. This lack of significance may have been due the relative simplicity of the search task, however, and several new experiments are proposed to further investigate whether repeated category information can benefit search.
Dissertation/Thesis
Masters Thesis Psychology 2014

This action research study compared student intellectual engagement between two different instructional delivery methods. The first instructional method was a non-contextual teaching approach using a textbook to teach the work outcomes for the S4 physics mechanics unit. The second instructional method was a contextual teaching approach where students built an electric guitar pickup and a simple electric guitar in order to provide a context for the teaching of the electromagnetism outcomes for the S4 physics electricity unit. To measure the intellectual engagement of students, data was collected from personal student journals and from questions generated by students following different instructional activities. The student generated questions were categorized and ranked to judge the degree of student intellectual engagement and depth of thought using a framework where numerical values were assigned to the questions. Each question was categorized as peripheral, factual, conceptual, or philosophical where the peripheral questions had the lowest intellectual ranking and the philosophical questions had the highest intellectual ranking. Data was also collected from cumulative unit tests, short exit slips and a personal teacher journal. The research revealed that students were more intellectually engaged and exhibited much more positive attitudes during the contextual lessons. The questions generated by students during the contextual lessons were of the higher order factual and conceptual types while the questions generated during the non-contextual lessons were predominantly of the lowest order peripheral type. By using the electric guitar and electric guitar pickup as a context, this action research study demonstrated that these contextual activities intellectually engaged students and helped to facilitate their deeper understanding of electromagnetism.

Considering the context of large city schools, this study explores what variables in a kindergarten classroom may impact the process of children’s engagement with nature. In particular I examine the central role of children and teacher in co-constructing their own unique understanding, knowledge, and attitude towards the natural world. In this study, I examine nature-child’s connection considering the complexity of nature beyond a pre-packaged concept (Louv, 2007) and avoiding a linear identification of a cause and effect relationship between children’s learning experiences and nature, (Kellert, 2005). This qualitative case study is based on extensive classroom observations, in which 20 kindergarten children and their teacher participate. The children’s direct, indirect, and vicarious experiences with nature are documented using digital photography, video-audio recording, and collection of artifacts. I interview the classroom teacher two times and invite the parents to fill up a questionnaire about their children’s experiences with nature outside the school time. I use the techniques and procedure of the grounded theory to analyze the data. A comparative analysis of the five learning episodes demonstrates four major factors that when all woven together encourage and sustain the children’s engagement with nature. These factors are: investigating children’s meaningful and autotelic questions, encountering and experiencing nature in familiar contexts, developing emotional bonding, and having sufficient time. The findings show the crucial role of the classroom teacher in creating five main conditions to engage the children in the process of each inquiry. She offers the children many opportunities to use their prior skills and knowledge, take responsibility of their own learning, and experiment with learning as a process. She often responds positively to the children’s learning endeavours and communicates her high confidence and expectations for them. This study makes an important contribution to the field of early childhood education and environmental education by demonstrating the possibilities and challenges in actively and holistically engaging children with nature in school settings. The findings shed light on our understanding of children and teacher’s sense of ownership and motivation as two driving forces of learning.