Academic literature on the topic 'Quasi-experimental method'
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Journal articles on the topic "Quasi-experimental method"
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Krasko, O. V. "Effect size assessment in quasi-experimental studies." Informatics 20, no. 1 (2023): 27–39. http://dx.doi.org/10.37661/1816-0301-2023-20-1-27-39.
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Objectives. To estimate effect sizes in quasi-experimental studies.Methods. Methods of the theory of estimation, methods of mathematical statistics.Results. Estimation of the effect size on an ordinal scale, estimation of the effect size on a binary in the case of opposite direction effects in groups, in quasi-experimental studies for the analytical method "differences in differences".Conclusion. The paper considers approaches to assessing absolute and standardized effect sizes in experimental and quasi-experimental studies. A brief review of the estimators of absolute and standardized effect sizes for quantitative and binary study variables is provided. The applied approach is proposed to assess the effect sizes of a binary variable in the case of opposite direction effects in groups within a quasi-experimental studies for the "differences in differences" analytical method. An example of assessment of absolute and standardized effect sizes of quantitative and binary variables in quasi-experimental studies in clinical epidemiology is considered.
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Kuś, Agnieszka. "Using quasi-experimental designs for causal effects." Scientific Papers of Silesian University of Technology. Organization and Management Series 2024, no. 194 (2024): 217–32. http://dx.doi.org/10.29119/1641-3466.2024.194.12.
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Purpose: This paper discusses the concept of identifying the causal effects using quasi-experimental methods and applies this method to investigate the impact of high license fees on the quality of mobile Internet in Poland. Design/methodology/approach: Quasi-experiment design, especially the difference-in-differences method and the interrupted time series design were used to examine the causal effects of spectrum fees in Poland. Data on the quality of mobile Internet in Poland and around the world published by Akamai and data provided by Ookla® under the agreement were used for analysis. Findings: The study did not confirm the impact of high spectrum fees on the quality of the Internet in Poland. Practical implications: The results obtained can help policymakers in Poland and other countries in making decisions on spectrum management. Originality/value: This is the first paper using the quasi-experimental method to examine the effects of the 4G auction in Poland. Keywords: quasi-experiment, difference in difference (DiD), interrupted time series design (ITS), spectrum auction, mobile Internet market. Category of the paper: Research paper.
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Monti, Maria Cristina, Stefano Maiandi, Lucia Rossi, Miriam Villani, and Cinzia Garofalo. "Nurse Handover with SBAR method: a quasi-experimental study." Dissertation Nursing 1, no. 1 (2022): 3–11. http://dx.doi.org/10.54103/dn/17691.
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BACKGROUND:Handover is a crucial aspect for patient safety and continuity of care. Many factors can affect the quality of the information transmitted and handover may be ineffective or even harmful if the information is incomplete or omitted. OBJECTIVES:The primary objective of the study was to describe the changes in handover quality after introduction of the Situation, Background, Assestment and Raccomandation (SBAR) method. Secondary objectives were to describe changes in the number of interruptions and changes in communication skills in nursing handover. MATHERIALS AND METHODS:A quasi-experimental, monocentric study with pre/post test design was implemented in a sample of convenience. RESULTS:198 nurses participated in the study and 208 nursing handovers were analyzed. After the introduction of the SBAR method there has been a significant improvement in the quality of handovers, a reduction in the number of interruptions and an increase in communication skills. CONCLUSION:SBAR method demonstrably improves the quality of nursing handovers, reducing the number of interruptions and enhancing communication skills. The introduction of the SBAR delivery method improves the quality and safety of information transmission.
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Darra, Maria, and Anastasia Papanthymou. "Research Designs and Methodologies of Studies in Student Self-Assessment: A Content Analysis." Journal of Studies in Education 9, no. 4 (2019): 1. http://dx.doi.org/10.5296/jse.v9i4.15438.
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The purpose of this paper is to analyze the content of 33 empirical studies related to student self-assessment in primary and secondary education and have been published over the last decade (2009-2019) in 19 scientific journals classified in Scimago (only articles in journals with peer review system to assure their quality) in order to investigate: a) the research design (experimental, quasi-experimental, non-experimental), b) the research method (mixed method, quantitative method, qualitative method), c) the specific design (pretest-posttest etc.), d) the data collection method (questionnaire, interviews, etc.). According to the main findings most studies use non-experimental design, followed by experimental and quasi-experimental design. With regard to research methods quantitative method is used in all research designs, while qualitative and mixed method are used to a lesser degree and only in experimental and non-experimental design. Regarding the specific design, most experimental and quasi- experimental studies adopt a "pretest-posttest" design, while non-experimental studies follow mainly descriptive design. Finally, concerning the data collection methods, questionnaire is the most common method for all research designs, as opposed to other methods, such as interview or the combination of questionnaire and interview. Therefore, there is a need to investigate the issue of student self-assessment using experimental or quasi-experimental research design where the mixed methodological approach will be adopted and data collection will be carried out using various research tools such as the interview and the questionnaire in order to triangulate the results.
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Getmanov, Victor, Vladislav Chinkin, Roman Sidorov, et al. "Low-Pass Filtering Method for Poisson Data Time Series." Applied Sciences 11, no. 10 (2021): 4524. http://dx.doi.org/10.3390/app11104524.
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Problems of digital processing of Poisson-distributed data time series from various counters of radiation particles, photons, slow neutrons etc. are relevant for experimental physics and measuring technology. A low-pass filtering method for normalized Poisson-distributed data time series is proposed. A digital quasi-Gaussian filter is designed, with a finite impulse response and non-negative weights. The quasi-Gaussian filter synthesis is implemented using the technology of stochastic global minimization and modification of the annealing simulation algorithm. The results of testing the filtering method and the quasi-Gaussian filter on model and experimental normalized Poisson data from the URAGAN muon hodoscope, that have confirmed their effectiveness, are presented.
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Reiser, Axel, and David G. Simmons. "A Quasi-experimental Method for Testing the Effectiveness of Ecolabel Promotion." Journal of Sustainable Tourism 13, no. 6 (2005): 590–616. http://dx.doi.org/10.1080/09669580508668583.
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BAO, L., and Y. D. HU. "EXPERIMENTAL SIMULATION OF FOREST ECOSYSTEM RESTORATION BY A QUASI-STATIC METHOD." Applied Ecology and Environmental Research 21, no. 3 (2023): 2229–39. http://dx.doi.org/10.15666/aeer/2103_22292239.
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Maulina, Maulina, Muhammad Ilham, and Andi Hamzah Fansury. "REVIEW OF RELATED LITERATURE ON RESEARCH METHODS APPLIED IN TEACHING GRAMMAR USING EDUCATIONAL TECHNOLOGY." KLASIKAL : JOURNAL OF EDUCATION, LANGUAGE TEACHING AND SCIENCE 4, no. 1 (2022): 1–18. http://dx.doi.org/10.52208/klasikal.v4i1.127.
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This paper involves researching, reading, analyzing, evaluating, and summarizing related scholarly literature about research methods used in teaching grammar, utilizing educational technology as one of the research learning sources for future related research. First, the reviewed scholarly article describes how the writers conducted their research. Then, using descriptive analysis, varieties of research methods in teaching grammar utilizing educational technology are investigated. Among the investigated research methods are quasi-experimental, phenomenology, ethnography, true experimental, pre-experimental, descriptive, mixed method of an exploratory study, mixed method of explanatory study, case study, survey method, classroom action research, and collaboration research. However, due to the limited space, the paper only describes popular methods of quantitative approach, including quasi-experimental, pre-experimental, true-experimental, survey studies. Besides, the qualitative approach involves case study, descriptive study, and phenomenology. Also, one of the most popular mixed-method used is explanatory study. The description of each method is supported by examples found in international and national journal articles published worldwide. This paper is expected to be beneficial to readers and researchers in English language teaching (ELT) worldwide.
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Lu, Xinmiao, Cunfang Yang, Qiong Wu, et al. "Improved Reconstruction Algorithm of Wireless Sensor Network Based on BFGS Quasi-Newton Method." Electronics 12, no. 6 (2023): 1267. http://dx.doi.org/10.3390/electronics12061267.
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Aiming at the problems of low reconstruction rate and poor reconstruction precision when reconstructing sparse signals in wireless sensor networks, a sparse signal reconstruction algorithm based on the Limit-Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) quasi-Newton method is proposed. The L-BFGS quasi-Newton method uses a two-loop recursion algorithm to find the descent direction dk directly by calculating the step difference between m adjacent iteration points, and a matrix Hk approximating the inverse of the Hessian matrix is constructed. It solves the disadvantages of BFGS requiring the calculation and storage of Hk, reduces the algorithm complexity, and improves the reconstruction rate. Finally, the experimental results show that the L-BFGS quasi-Newton method has good experimental results for solving the problem of sparse signal reconstruction in wireless sensor networks.
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Awansyah, Patra. "PENERAPAN METODE EKSPERIMEN UNTUK MENINGKATKAN SIKAP ILMIAH DAN PRESTASI BELAJAR SISWA." Diadik: Jurnal Ilmiah Teknologi Pendidikan 12, no. 1 (2022): 121–230. http://dx.doi.org/10.33369/diadik.v12i1.21390.
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This study aims to describe the scientific attitudes and student achievement and to determine the effectiveness of the application of experimental methods on student achievement. The method used in this research is a combination method of classroom action research and quasi-experimental research. The subjects of the classroom action research were students of grade V SD Negeri 9 Tanjung Sakti Pumu for the academic year 2020/2021 even semester totaling 22 students. The population in this quasi-experimental research was all grade V students of the State Elementary School of Gugus II Tanjung Sakti Pumu. The research sample was selected by two classes in SD Negeri 9 Tanjung Sakti Pumu, namely class Va and Vb. Data collection techniques using observation sheets and tests. Data analysis using mean (mean) and t-test. The results of the study concluded that: The application of experimental methods can improve students' scientific attitudes; The application of the experimental method can significantly improve student achievement, and the application of the experimental method can effectively improve student achievement
Dissertations / Theses on the topic "Quasi-experimental method"
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Wirén, Sacharias. "Working against anti-religious prejudice? : A mixed-method evaluation of ‘Together for Sweden’s storytelling method from a social psychology perspective." Thesis, Uppsala universitet, Teologiska institutionen, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-412802.
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The purpose of this study was to provide an initial evaluation of the effect of ‘Together for Sweden’s (TFS) storytelling method regarding anti-religious prejudice, based on a social identity perspective. Furthermore, the aim was to understand the possible self-perceived changes that the storytelling method contributes to regarding anti-religious prejudice. The study applied a mixed-method approach with a quasi-experimental design. The quantitative data collection consisted of a pre-and posttest with an experiment and control condition. The qualitative data collection consisted of semi-structured interviews with participants from the experiment condition. The quantitative results point to a positive self-perceived change in anti-religious prejudice. However, the change was small and not statistically significant in relation to the control condition. The qualitative find suggests that for some participants, the storytelling could provide an opportunity for a positive intergroup contact, counter-examples, counter-stereotypic information as well as addressing the categorization process through multiple and shared group memberships. The qualitative findings also point to a change regarding the view of religious people but not concerning the view of religion. This, together with a mixed response regarding affective shifts and a lack of intentional shifts, can help to explain the quantitative results. The findings of the study address the need to evaluate prejudice-reduction intervention in a school context as well as the need to test a social identity perspective outside a laboratory context. It also provided a first and tentative assessment of TFS’ storytelling method, which can contribute to a further adjustment of the method or future in-schools interventions.
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Louati, Haithem. "Experimental and numerical study of humid granular material : influence of liquid content in quasi-static regime." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2016. http://www.theses.fr/2016EMAC0008/document.
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Cette thèse est une étude expérimentale et numérique du comportement au cisaillement de milieu granulaire humide sous l’effet de la quantité de liquide introduite et la contrainte normale appliquée. Les expériences ont été faites sur une cellule de cisaillement annulaire, pour une large gamme de contraintes appliquées allant de presque 0.3 kPa à 12 kPa. Les résultats donnent la variation de la contrainte de cisaillement en régime stationnaire en fonction de la contrainte normale pour une large variation de la quantité de liquide. Le liquide dans le milieu granulaire va de ponts liquides formés au point de contact jusqu’au remplissage totale de l'espace entre les grains. L’effet de liquide sur la résistance au cisaillement et la porosité de milieu granulaire a été analysé. Différents régimes du comportement de milieu granulaire humide ont été identifiés. Afin d’acquérir une compréhension microscopique du comportement au cisaillement de milieu granulaire sec et partiellement humide, la méthode des éléments discrets (DEM) a été utilisée. Des billes de verre de grande taille (2 mm de diamètre) ont été utilisées pour réduire le temps de simulation et faciliter la caractérisation à l’échelle de particule. Une première partie a été consacrée à l’étude de l’effet des propriétés microscopiques de particule (Module de Young et la friction de glissement) sur les propriétés macroscopiques de milieu granulaire sec et humide (le nombre de coordination, la porosité, le ratio de contraintes et la vitesse de particules). Une deuxième partie a été concernée par l’étude du comportement au cisaillement de milieu granulaire humide pour différentes fractions de liquide et différentes contraintes normales appliquées. En particulier, les forces capillaires et le nombre de ponts liquide ont été quantitativement analysés<br>We study experimentally and numerically the shear behaviour of wet granular material. We investigate the effect of the liquid content and the applied normal stresses to this behaviour. An annular shear cell was used to carry out the experiments, for a large range of applied normal stress from about 0.3 kPa to 12 kPa. The results give the variation of the shear stress at steady-state as a function of the normal stress for a wide range of liquid fraction. The incorporated liquid goes from forming bridges at the contact point to completely filling the space between grains. The shear resistance and the voidage fraction variations with the liquid fraction were analysed. Depending on the applied normal stress and the liquid fraction, different regimes of the shear resistance were identified. The discrete element method (DEM) was used to gain a microscopic understanding of the shear behaviour of dry and partially wet granular material in the shear cell. Large size glass beads were used to speed up the computational time and to facilitate characterisation at the particle scale. First, the influence of the microscopic properties of the particle (The Young’s modulus and the sliding friction) on the macroscopic properties of dry and wet granular materials (the coordination number, the voidage fraction, the shear ratio and the velocity of particles) was investigated. Secondly, the shear behaviour of the partially wet granular material for different liquid fractions and normal stresses was studied. The capillary forces and the number of liquid bridges were quantitatively analysed
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Zobec, Helena, and helena zobec@canberra edu au. "An investigation of library literacy levels of flexible learners at the Canberra Institute of Technology: a pilot study." University of Canberra. Information Management & Tourism, 1998. http://erl.canberra.edu.au./public/adt-AUC20050809.143304.
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The present study attempted to measure library literacy levels of open or flexible
learners at the Canberra Institute of Technology (CIT) during the 1995 academic year,
and to investigate to what extent the information skills component of TAFE open
learning modules influence adult learners' library literacy levels.
To address these issues, a quasi-experimental research methodology was used to
measure library literacy levels at the beginning and, again, on or near course
completion to ascertain whether any change had occurred, through the administration
of a questionnaire. A number of participants were then interviewed to further validate
the responses fiom the questionnaires.
The study attempted to show that though courses claim to address key competencies
in a vocational education and training environment, one component of the key
competencies, the ability to collect, analyse and organise information, was not being
met. That one component was the ability to locate (or collect) information.
No strong correlations resulted fiom the library literacy levels measured and the
degree to which the key competency was addressed within course modules. No
statistical measures were possible due to the small sample population that eventuated,
though it was almost half the original targeted population. No real gain was achieved
in library literacy levels between the pretest and posttest stages of the research for
either the Experimental or Control groups. Though a highly suitable research
methodology, the quasi-experimental research design did have some limitations in this
piece of research. The CIT flexible learning environment at the time of the study
contributed to the limitations of the study.
However, a number of recommendations were made on the basis of the research
results, advocating some strategies that might be implemented to improve the library
literacy levels of learners undertaking open or flexible delivery courses within CIT,
and suggestions to change the research environment to avoid many of the problems
experienced.
The CIT pilot study was the first known formally documented study of library literacy
levels in an Australian TAFE environment of its kind. The study reflects the literature
published at the time of the study. At that time, the research in this field was minimal.
Many publications and research have emerged since 1995 when this study was
conducted, indicating this is an area of great interest.
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Miranda, Montero Juan Jose. "Essays on Experimental and Quasi-Experimental Policy Design and Evaluation." Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/econ_diss/86.
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This dissertation comprises two essays. The unifying theme is the evaluation of non-pecuniary (information or norm based messages) conservation programs. These types of policies are widely applied in developing and developed countries to promote conservation, however, their empirical evidence and their effectiveness are not well documented. Each chapter examines some methodological facets of the heterogeneity of non-pecuniary conservation programs and the reliability of non-experimental methods (program evaluation and econometric techniques) to evaluate treatment effects in the context of non-pecuniary conservation programs.
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Stoeffler, Quentin. "Three Essays on Poverty in Sub-Saharan Africa: Multidimensional Poverty Change in Zimbabwe; Long-Term Impact of Cash Transfers in Niger; and Targeting Efficiency of Social Protection Programs in Cameroon." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/50444.
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This dissertation focuses on identifying the poor in Sub-Saharan Africa (SSA) and the potential of social assistance programs to address their condition. Each essay is related to one particular key step of the poverty alleviation agenda: poverty definition and measurement in Zimbabwe; targeting poor households in Cameroon; and impact evaluation of anti-poverty interventions in Niger.
The first essay explores changes in poverty across multiple dimensions in a period of dramatic economic crisis and recovery in Zimbabwe. The essay analyzes changes in household well-being between 2001, 2007 and 2011/12, using an Alkire-Foster multidimensional poverty index. Results indicate a large increase in multidimensional poverty across between 2001 and 2007, followed by a (smaller) decrease in poverty between 2007 and 2011/12 (recovery period after the hyperinflation peak in 2008). However, decomposition of the index shows significantly different trends in poverty dimensions over time, as for instance health related dimensions continued to deteriorate after 2007.
The second essay contributes to the policy debate on targeting by studying the ex-post efficiency of two targeting mechanisms employed in a cash transfer project in rural Cameroon: Proxy Means Testing (PMT) and community targeting. Results show a poor performance of community targeting in selecting households with low per capita consumption, compared to PMT targeting—whose errors remain high nonetheless. Communities tend to select small, isolated households with low physical and human capital, regardless of their actual consumption level, but produce variable outcomes. Overall results suggest that a higher coverage contributes to reducing targeting errors, and that better guidance should be provided to communities if the policy objective is to select low per capita consumption individuals.
The third essay investigate whether cash transfers induce investments in assets and productive activities that survive the termination of program payments using data from an unconditional cash transfer project in Niger 18 months after its termination. Based on quasi-experimental methods, results indicate that local saving/credit systems (tontines) participation and livestock ownership significantly increased among project participants. There is also evidence of improvement in private assets, micro-enterprises and agriculture. The findings imply that cash transfer programs can have long-term sustainable impacts in rural SSA.<br>Ph. D.
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Watanabe, Emerson Ferrell. "A Quasi-Experimental Study of the Effect of Experience Staging Techniques on Engagement." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7555.
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The purpose of this study is to examine the effect of experience staging techniques (personalization through co-creation and multisensory stimuli) on engagement level. This study also explores the possible contribution of experience staging techniques as practical tools that recreation professionals can use to better engage participants in recreation activities and events. A 2-way univariate ANOVA revealed no significant relationship between the use of co-creative and multisensory stimulating techniques and engagement levels in participants (F (3,200) = .263, p = .826, partial η2 = .004). Practical applications for recreation professionals and further research opportunities are discussed.
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Garabedian, Laura Faden. "Quasi-Experimental Health Policy Research: Evaluation of Universal Health Insurance and Methods for Comparative Effectiveness Research." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10764.
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This dissertation consists of two empirical papers and one methods paper. The first two papers use quasi-experimental methods to evaluate the impact of universal health insurance reform in Massachusetts (MA) and Thailand and the third paper evaluates the validity of a quasi-experimental method used in comparative effectiveness research (CER).
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Bristor, Valerie Jayne. "A quasi-experimental comparison of the test-study and study-test methods in fourth grade spelling." Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/536295.
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The purpose of this study was to compare two methods of spelling instruction, the test-study method and study-test method, with the spelling achievement of selected fourth grade students. The effects of gender and spelling ability level on the spelling method were also studied. The participants were 80 fourth grade students from four intact classrooms in two elementary schools in a small suburban midwestern school district.Third grade standardized test scores were collected from students' permanent record cards and used for grouping students into spelling ability levels. A Spelling Criterion-Referenced Test was used as a pretest (covariate) and a posttest (dependent variable). An analysis of covariance was used to test three null hypotheses at the .05 level of significance. The three null hypotheses were not rejected. The following results were suggested:1. Both fourth grade boys and girls achieve equally well in spelling whether they use the test-study method or the study-test method of spelling instruction.2. Fourth grade students achieve equally well in spelling whether they use the test-study method or the study-test method of spelling instruction.3. Fourth grade girls and boys achieve equally well in spelling.Teachers should consider integrating spelling into all areas of the language arts by supplementing the spelling textbook with words the children are using in their writing.<br>Department of Elementary Education
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Zhang, Tianyu. "Problème inverse statistique multi-échelle pour l'identification des champs aléatoires de propriétés élastiques." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC2068.
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Dans le cadre de la théorie de l'élasticité linéaire, la modélisation et simulation numérique du comportement mécanique des matériaux hétérogènes à microstructure aléatoire complexe soulèvent de nombreux défis scientifiques à différentes échelles. Bien qu'à l'échelle macroscopique, ces matériaux soient souvent modélisés comme des milieux homogènes et déterministes, ils sont non seulement hétérogènes et aléatoires à l'échelle microscopique, mais ils ne peuvent généralement pas non plus être explicitement décrits par les propriétés morphologiques et mécaniques locales de leurs constituants. Par conséquent, une échelle mésoscopique est introduite entre l'échelle macroscopique et l'échelle mésoscopique, pour laquelle les propriétés mécaniques d'un tel milieu élastique linéaire aléatoire sont décrites par un modèle stochastique prior non-gaussien paramétré par un nombre faible ou modéré d'hyperparamètres inconnus. Afin d'identifier ces hyperparamètres, une méthodologie innovante a été récemment proposée en résolvant un problème statistique inverse multi-échelle en utilisant uniquement des données expérimentales partielles et limitées aux deux échelles macroscopique et mésoscopique. Celui-ci a été formulé comme un problème d'optimisation multi-objectif qui consiste à minimiser une fonction-coût multi-objectif (à valeurs vectorielles) définie par trois indicateurs numériques correspondant à des fonctions-coût mono-objectif (à valeurs scalaires) permettant de quantifier et minimiser des distances entre les données expérimentales multi-échelles mesurées simultanément aux deux échelles macroscopique et mésoscopique sur un seul échantillon soumis à un essai statique, et les solutions des modèles numériques déterministe et stochastique utilisés pour simuler la configuration expérimentale multi-échelle sous incertitudes. Ce travail de recherche vise à contribuer à l'amélioration de la méthodologie d'identification inverse statistique multi-échelle en terme de coût de calcul, de précision et de robustesse en introduisant (i) une fonction-coût mono-objectif (indicateur numérique) supplémentaire à l'échelle mésoscopique quantifiant la distance entre la(les) longueur(s) de corrélation spatiale des champs expérimentaux mesurés et celle(s) des champs numériques calculés, afin que chaque hyperparamètre du modèle stochastique prior ait sa propre fonction-coût mono-objectif dédiée, permettant ainsi d'éviter d'avoir recours à l'algorithme d'optimisation global (algorithme génétique) utilisé précédemment et de le remplacer par un algorithme plus performant en terme d'efficacité numérique, tel qu'un algorithme itératif de type point fixe, pour résoudre le problème d'optimisation multi-objectif avec un coût de calcul plus faible, et (ii) une représentation stochastique ad hoc des hyperparamètres impliqués dans le modèle stochastique prior du champ d'élasticité aléatoire à l'échelle mésoscopique en les modélisant comme des variables aléatoires, pour lesquelles les distributions de probabilité peuvent être construites en utilisant le principe du maximum d'entropie sous un ensemble de contraintes définies par les informations objectives et disponibles, et dont les hyperparamètres peuvent être déterminés à l'aide de la méthode d'estimation du maximum de vraisemblance avec les données disponibles, afin d'améliorer à la fois la robustesse et la précision de la méthode d'identification inverse du modèle stochastique prior. En parallèle, nous proposons également de résoudre le problème d'optimisation multi-objectif en utilisant l’apprentissage automatique par des réseaux de neurones artificiels. Finalement, la méthodologie améliorée est tout d'abord validée sur un matériau virtuel fictif dans le cadre de l'élasticité linéaire en 2D contraintes planes et 3D, puis illustrée sur un matériau biologique hétérogène réel (os cortical de bœuf) en élasticité linéaire 2D contraintes planes<br>Within the framework of linear elasticity theory, the numerical modeling and simulation of the mechanical behavior of heterogeneous materials with complex random microstructure give rise to many scientific challenges at different scales. Despite that at macroscale such materials are usually modeled as homogeneous and deterministic elastic media, they are not only heterogeneous and random at microscale, but they often also cannot be properly described by the local morphological and mechanical properties of their constituents. Consequently, a mesoscale is introduced between macroscale and microscale, for which the mechanical properties of such a random linear elastic medium are represented by a prior non-Gaussian stochastic model parameterized by a small or moderate number of unknown hyperparameters. In order to identify these hyperparameters, an innovative methodology has been recently proposed by solving a multiscale statistical inverse problem using only partial and limited experimental data at both macroscale and mesoscale. It has been formulated as a multi-objective optimization problem which consists in minimizing a (vector-valued) multi-objective cost function defined by three numerical indicators corresponding to (scalar-valued) single-objective cost functions for quantifying and minimizing distances between multiscale experimental data measured simultaneously at both macroscale and mesoscale on a single specimen subjected to a static test, and the numerical solutions of deterministic and stochastic computational models used for simulating the multiscale experimental test configuration under uncertainties. This research work aims at contributing to the improvement of the multiscale statistical inverse identification method in terms of computational efficiency, accuracy and robustness by introducing (i) an additional mesoscopic numerical indicator allowing the distance between the spatial correlation length(s) of the measured experimental fields and the one(s) of the computed numerical fields to be quantified at mesoscale, so that each hyperparameter of the prior stochastic model has its own dedicated single-objective cost-function, thus allowing the time-consuming global optimization algorithm (genetic algorithm) to be avoided and replaced with a more efficient algorithm, such as the fixed-point iterative algorithm, for solving the underlying multi-objective optimization problem with a lower computational cost, and (ii) an ad hoc stochastic representation of the hyperparameters involved in the prior stochastic model of the random elasticity field at mesoscale by modeling them as random variables, for which the probability distributions can be constructed by using the maximum entropy principle under a set of constraints defined by the available and objective information, and whose hyperparameters can be determined using the maximum likelihood estimation method with the available data, in order to enhance both the robustness and accuracy of the statistical inverse identification method of the prior stochastic model. Meanwhile, we propose as well to solve the multi-objective optimization problem by using machine learning based on artificial neural networks. Finally, the improved methodology is first validated on a fictitious virtual material within the framework of 2D plane stress and 3D linear elasticity theory, and then illustrated on a real heterogenous biological material (beef cortical bone) in 2D plane stress linear elasticity
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Levi, Altstaedter Laura. "Writing Instruction in Foreign Language Courses: Multiple Perspectives on the Impact of Peer Feedback on Students’ Writing Proficiency." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/28384.
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Grounded in sociocultural theory, peer feedback can help students engage in interaction and negotiation of meaning, which serve as a basis for the construction of knowledge (Vygotsky, 1978). It can also contribute to the development of self-regulation, as well as of reflection on one's own learning (Doolittle & Hicks, 2003). Its strategic incorporation into foreign language instruction can help students use the language they are in the process of acquiring to mediate language acquisition (Shrum & Glisan, 2005).
Research shows that peer feedback can help students develop and advance their Zone of Proximal Development through their engagement in collaborative interaction with their peers (De Guerrero & Villamil, 1994, 2000; Donato, 2004; Lantolf, 2004; Lantolf & Thorne, 2006; Liu & Hansen, 2005). Peer feedback can also help students improve their writing proficiency, including organization of their texts and awareness of the mechanics of the language necessary for successful communication of the intended message (Kinsler, 1990; Hu, 2005; Williams, 2005).
Framed within a sociocultural perspective on foreign language learning and development, and following a manuscript approach, this dissertation consists of a series of studies that aim to explore: (a) whether participation in a peer feedback experience has a positive impact on students’ foreign language writing proficiency; (b) whether guidelines plus training in how to provide meaningful feedback have a different impact on students’ foreign language writing proficiency than guidelines alone; (c) around what themes students focus the feedback they provide to their peers; and (d) what students’ perceptions of the peer feedback experience are.
The results of the first the study, which consisted of a pre-test post-test quasi-experimental design, showed that students significantly improved their writing proficiency after participating in a peer feedback experience, regardless of training. Further the results of this study indicated that, on average, trained and untrained students provided written peer feedback focused mainly on global aspects rather than local aspects. The results of the second study, which consisted of a mixed methods approach, showed that, on average, students had high perceptions of the peer feedback experience and that they perceived that their partner's feedback had helped them improve the global aspects of their composition more than the local aspects. Students expressed that what they liked the most about the experience was getting a different perspective on their writing, and what they liked the least was that they felt they were not proficient enough in the foreign language to provide meaningful feedback to their peers.<br>Ph. D.
Books on the topic "Quasi-experimental method"
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Olofsson, Åke. Phonemic awareness and learning to read: A longitudinal and quasi-experimental study. University of Umeå, 1985.
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Nichols, Marcia, Andrew M. Petzold, and Robert L. Dunbar. Challenges of Using the Classroom as a Quasi-Experimental Research Environment for Teacher-Scholars and the Importance of a Mixed-Methods Approach. SAGE Publications Ltd, 2025. https://doi.org/10.4135/9781036214043.
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Klimenko, Marina, and Kyle W. Williams. Can Engagement in a Research Project Increase Online Undergraduate Students’ Science Self-Efficacy? A Quasi-Experimental Study of Online Students in a Research Methods Class. SAGE Publications Ltd, 2025. https://doi.org/10.4135/9781036215644.
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Miksza, Peter, and Kenneth Elpus. Advances in Quasi-experimental Methods. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199391905.003.0015.
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Although the primacy of the randomized experiment is often thought of as sacrosanct, in education research—and in music education research in particular—random assignment is often unachievable, unethical, or undesirable for one or more of many potential reasons. Methodologists have developed quasi-experimental research methods that attempt to achieve results that approximate the highly trustworthy results obtained from a randomized experiment. This chapter details two newer methods for quasi-experimental research that have become quite common in the broader field of education but have not yet become frequently employed within the field of music education research. These two methods are regression discontinuity designs and the use of propensity scores for the equating of nonequivalent groups.
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Miksza, Peter, and Kenneth Elpus. Causation and Causal Claims. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199391905.003.0007.
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This chapter explores the philosophy of science surrounding warrants for causal claims, how researchers can use quantitative data to create causal knowledge, and how to evaluate the validity of causal knowledge generated through research. In music education, carefully answered causal questions can provide insights that improve both teaching and learning in music at all levels and in all contexts. In this chapter, details are provided on the kinds of experimental and quasi-experimental research designs most commonly employed for causal research, the challenges that researchers using these methods often face, and specific threats to validity that commonly occur in those designs.
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Hens, Kristien, James R. Beebe, Hagop Sarkissian, et al., eds. Advances in Experimental Philosophy of Medicine. Bloomsbury Publishing Plc, 2023. http://dx.doi.org/10.5040/9781350281554.
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This open access collection brings together a team of leading scholars and rising stars to consider what experimental philosophy of medicine is and can be. While experimental philosophy of science is an established field, attempts to tackle issues in philosophy of medicine from an experimental angle are still surprisingly scarce. A team of interdisciplinary scholars demonstrate how we can make progress by integrating a variety of methods from experimental philosophy, including experiments, sociological surveys, simulations, as well as history and philosophy of science, in order to yield meaningful results about the core questions in medicine. They focus on concepts central to philosophy of medicine and medical practice, such as death, pain, disease and disorder, advance directives, medical explanation, disability and informed consent. Presenting empirical findings and providing a crucial foundation for future work in this dynamic field, this collection explores new ways for philosophers to cooperate with scientists and reveals the value of these collaborations for both philosophy and medicine. The eBook editions of this book are available open access under a CC BY-NC-ND 4.0 licence on bloomsburycollections.com. Open access was funded by the European Research Council Starting Grant. This volume presents a sample of exciting new ‘naturalistic’ work on quasi-perennial topics in the philosophy of medicine, such as the demarcation of disease, life, death, pain and disability. Some chapters engage surveys and vignettes, others use corpus analysis or simulations, while others offer interesting reflections on how such experimental philosophy touches upon other new developments in philosophy (of medicine), such as conceptual engineering. A couple of contributions mainly focus on the limitations of experimental philosophy of medicine, and point out potential problems with its assumptions or goals.
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Gugerty, Mary Kay, and Dean Karlan. The CART Principles for Impact Evaluation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199366088.003.0006.
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The CART principles are essential for designing a right-fit impact evaluation. This chapter explains what it means to conduct credible, actionable, responsible, and transportable impact evaluation. To ensure that impact evaluations follow the CART principles, organizations ought to strive for bias-free data collection and analysis. Bias (systematic error that favors one measure over another) may come from the way data are collected (question wording influences responses), or the way they are analyzed (e.g., influence of external factors or how people are selected into programs). In many cases, an randomizied control trial (RCT) helps generate a credible impact evaluation. In the simplest version of an RCT, individuals are randomly assigned to treatment and control groups. However, in special circumstances, other quasi-experimental evaluation methods can be successful. Actionable impact evaluation requires that organizations commit to learn from the undertaking and act on the results, even if they are disappointing. Organizations can make sure an evaluation is responsible by weighing how much it costs relative to its expected benefits. This chapter also addresses common criticisms about RCTs and identifies some strategies for reducing their cost. Finally, the chapter explains that the transportable principle mandates that evaluations produce useful evidence for others.
Book chapters on the topic "Quasi-experimental method"
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Hamelin, P., A. Gabor, T. Q. Bach, and A. Si Larbi. "Optimization of Quasi-isotropic Formulation of Fiber-Cement Laminates: Polar Method and Experimental Validation." In High Performance Fiber Reinforced Cement Composites 6. Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-2436-5_57.
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Bennett, Andrew. "Causal Inference and Policy Evaluation from Case Studies Using Bayesian Process Tracing." In Texts in Quantitative Political Analysis. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-12982-7_8.
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AbstractCase studies enable policy-relevant causal inferences when experimental and quasi-experimental methods are not possible. Even when other methods are possible, case studies can strengthen inferences either as a standalone method or as part of a multimethod research design. The chapter outlines the case study method of process tracing (PT), which is a within-case mode of analysis that builds upon Bayesian logic to make inferences to the best explanation of the outcomes of single cases. The chapter locates the epistemological basis of PT in the development and testing of theories about the ways in which causal mechanisms operate to generate outcomes. It then defines PT and outlines best practices on how to do it, illustrating these with examples of case study research on the COVID pandemic. The chapter then outlines the comparative advantages of PT vis-à-vis other methods, and identifies the kinds of research questions and research contexts for which PT is most useful. This leads to a brief discussion of two methodological innovations: formal Bayesian PT and the use of causal models in the form of Directed Acyclic Graphs to assist PT and integrate qualitative and quantitative evidence. The chapter concludes with the strengths and limits of PT.
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Barrio Minton, Casey A. "Quasi-Experimental Methods." In Making Research Relevant. Routledge, 2018. http://dx.doi.org/10.4324/9781315179353-8.
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Barrio Minton, Casey A. "Quasi-Experimental Methods." In Making Research Relevant, 2nd ed. Routledge, 2024. http://dx.doi.org/10.4324/9781032706139-9.
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Aldianto, Leo, and Grisna Anggadwita. "Indonesia: How Effective Is Direct Storytelling in Enhancing Entrepreneurial Motivation for Visually Impaired People? An Experimental Study." In Start-up Cultures in Times of Global Crises. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-53942-8_12.
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AbstractPeople with visual impairment have limitations in carrying out socioeconomic activities. The entrepreneurial initiative is an attempt to encourage the active participation of visually impaired people in improving their socioeconomic status. Managing motivation is essential for increasing the self-confidence and potential of people with visual impairments. Storytelling is a method that is considered capable of providing cognitive stimulation to visually impaired persons to generate entrepreneurial motivation. Thus, this study aims to identify the effectiveness of the storytelling method in increasing the entrepreneurial motivation of visually impaired people. This study used a quasi-experimental design by comparing treatment and control groups. Statistical analysis was performed to test the results of the pre- and post-tests. This study was conducted at a social institution in Indonesia for the visually impaired. The results of this study show that direct storytelling is an effective method for increasing entrepreneurial motivation in people with visual impairments. Statistical tests showed a difference between the experimental and control groups after the storytelling intervention, significantly increasing entrepreneurial motivation. This study provides new insights into entrepreneurship by using a storytelling method. This study also presents policy implications for developing empowerment models for persons with disabilities, particularly the entrepreneurial approach for visually impaired people.
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Newhart, Michelle, and Mildred L. Patten. "Quasi-Experimental Designs." In Understanding Research Methods, 11th ed. Routledge, 2023. http://dx.doi.org/10.4324/9781003092049-41.
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Patten, Mildred L., and Michelle Newhart. "Quasi-Experimental Designs." In Understanding Research Methods. Routledge, 2017. http://dx.doi.org/10.4324/9781315213033-63.
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Levesque, Roger J. R. "Experimental and Quasi-Experimental Methods." In Encyclopedia of Adolescence. Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-1695-2_655.
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Levesque, Roger J. R. "Experimental and Quasi-Experimental Methods." In Encyclopedia of Adolescence. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-33228-4_655.
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Chow, Jason C. "Quasi-Experimental Designs." In Research Methods in Special Education. Routledge, 2024. http://dx.doi.org/10.4324/9781003526315-9.
Full textConference papers on the topic "Quasi-experimental method"
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Erhard, Racheal, and Juan Alonso. "A Quasi-Prescribed Vortex Wake Method Capturing Rotor Wake Distortion." In Vertical Flight Society 80th Annual Forum & Technology Display. The Vertical Flight Society, 2024. http://dx.doi.org/10.4050/f-0080-2024-1116.
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Prescribed vortex wake methods have historically provided rapid analysis for modeling rotor performance with reasonable accuracy suitable to conceptual and preliminary design. However, determining an appropriate wake geometry requires accurate prescription functions, often relying on empirical data. For distributed electric propulsion (DEP) and electric vertical takeoff and landing (eVTOL) aircraft, interaction effects of installed multi-rotor and rotor-wing systems can introduce significant wake distortion and deflection, which is not captured by a rigid or prescribed wake model. Force-free wake methods can capture these wake interactions, but at significant computational cost. To maintain rapid analysis capabilities while capturing external wake interactions, we develop an approach for an adaptive quasi-prescribed vortex wake method. The proposed approach is developed using principles of potential flow theory and a relaxation procedure to include the mutual wake interaction between aircraft components. Applications to rotor-wing systems with coupling between the rotor wake and a vortex lattice method representation of the wing is explored. Results are compared with two additional methods that have been developed, a prescribed vortex wake and a free vortex wake. Validation against experimental measurements for a blown wing configuration is conducted, and the method's ability to more closely predict wake distortion of a tilt-rotor and wing system is also explored.
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Zhu, Kangqi, Nan Hua, and Xiaoping Zheng. "Sub-Nanosecond Time Synchronization Method by Quasi-Dual-Frequency Distributed Time Synchronization in Time-Varying Optical Satellite Network." In Optical Fiber Communication Conference. Optica Publishing Group, 2025. https://doi.org/10.1364/ofc.2025.th3d.6.
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We propose a cost-effective quasi-dual-frequency time synchronization method for time-varying optical satellite networks. The experimental results demonstrate that the prototype system can achieve 0.536-ns synchronization accuracy, which is 2 orders higher than the clock resolution.
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Wang, Y., J. A. Wharton, J. Downes, and R. A. Shenoi. "Marine Structural Integrity Subject to Mechano-electrochemical Induced Corrosion." In CORROSION 2017. NACE International, 2017. https://doi.org/10.5006/c2017-09656.
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Abstract Carbon steel marine platforms, including ships and offshore structures, are at high risk of corrosion due to the combination of aggressive seawater environment, corrosive cargoes and constantly changing loading conditions. In particular, the combined influence of mechanical and electrochemical effects (which is often termed mechano-electrochemistry) has gained increasing attention over the last decade. Although various experiments, along with theoretical/empirical expressions, have been proposed to establish the relationship between stress/strain and the corrosion behavior, there are few in situ measurements of corrosion and the mechanical properties. Moreover, such corrosion mechanisms have not been incorporated for large scale ship or offshore structural members. This work has developed an experimental protocol including in situ potentiostat and quasi-static tensile tests to provide an improved understanding of the corrosion behavior of UNS G10210 steel at different stress levels. A novel local-global finite element method has been proposed to model a steel plate at a ship compartment scale under uniaxial quasi-static tensile/compressive loading. The stress distributions together with the experimental measurements were utilized to simulate a local mechano-electrochemical corrosion process and predict the stress-induced corrosion rate change. The modeling results demonstrate a more realistic approach to estimate marine structural integrity considering stress-induced localized corrosion.
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Nili-Ahmadabadi, Mahdi, Mohammad Durali, and Ali Hajilouy-Benisi. "A Novel Quasi 3-D Design Method for Centrifugal Compressor Meridional Plane." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23341.
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This paper is concerned with a quasi-3D design method for centrifugal compressor impeller in the meridional plane. The method links up a novel inverse design algorithm, called Ball-Spine Algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain of which some unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, the unknown walls are composed of a set of virtual balls that move freely along the specified directions called spines. The difference between target and current pressure distribution causes to deform flexible boundary at each modification step. In order to validate the quasi-3D analysis code, an existing compressor is investigated by some experiments in which several static pressure points on the shroud, the flow parameters at the compressor inlet and outlet are measured. Comparison of the quasi-3D analysis results with experimental results shows good agreement. Also, a full 3D Navier-Stokes code is used to analyze the existing and designed compressor numerically. The results show that the momentum decrease near the shroud wall in the existing compressor is removed by hub-shroud modification resulting an improvement in performance by 0.6 percent.
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Sawadogo, Teguewinde, and Njuki Mureithi. "A Method for Extracting the Time Delay From the Unsteady and Quasi-Steady Fluidelastic Forces in Two-Phase Flow." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97437.
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The time delay is a key parameter for modeling fluidelastic instability, especially the damping controlled mechanism. It can be determined experimentally by measuring directly the time lag between the tube motion and the induced fluid forces. The fluid forces may be obtained by integrating the pressure field around the moving tube. However, this method faces certain difficulties in two-phase flow since the high turbulence and the non-uniformity of the flow may increase the randomness of the measured force. To overcome this difficulty, an innovative method for extracting the time delay inherent to the quasi-steady model for fluidelastic instability is proposed in this study. Firstly, experimental measurements of unsteady and quasi-static fluid forces (in the lift direction) acting on a tube subject to two-phase flow were conducted. The unsteady fluid forces were measured by exciting the tube using a linear motor. These forces were measured for a wide range of void fraction, flow velocities and excitation frequencies. The experimental results showed that the unsteady fluid forces could be represented as single valued function of the reduced velocity (flow velocity reduced by the excitation frequency and the tube diameter). The time delay was determined by equating the unsteady fluid forces with the quasi-static forces. The results given by this innovative method of measuring the time delay in two-phase flow were consistent with theoretical expectations. The time delay could be expressed as a linear function of the convection time and the time delay parameter was determined for void fractions ranging from 60% to 90%. Fluidelastic instability calculations were also performed using the quasi-steady model with the newly measured time delay parameter. Previously conducted stability tests provided the experimental data necessary to validate the theoretical results of the quasi-steady model. The validity of the quasi-steady model for two-phase flow was confirmed by the good agreement between its results and the experimental data. The newly measured time delay parameter has improved significantly the theoretical results, especially for high void fractions (90%). However, the model could not be verified for void fractions lower or equal to 50% due to the limitation of the current experimental setup. Further studies are consequently required to clarify this point. Nevertheless, this model can be used to simulate the flow induced vibrations in steam generators’ tube bundles as their most critical parts operate at high void fractions (≥ 60%).
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Jia, Xinlong, Nan Gui, Xingtuan Yang, Jiyuan Tu, and Shengyao Jiang. "Experimental and Numerical Study of the Movement Mechanism and Characteristics of the Quasi-Static Pebble Flow." In 2013 21st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icone21-15371.
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Quasi-static pebble flow, or so-called the very slow pebble flow, in a pebble bed reactor, with evident randomicity and dispersibility, is extremely complex. Improving the knowledge of the movement mechanism of quasi-static pebble flow can be beneficial to the safety of the pebble bed reactor. This study utilizes a phenomenological method and a discrete element method to investigate the interface features of two regions composed of differently colored pebbles. A pseudo-two dimensional experimental setup is established to facilitate the observation of movement of pebble. Then, the DEM simulation is carried out to analyze the further details of particle movement mechanism. To some extent, the two methods are closely related and mutually confirmed. In this study, some special phenomena are observed, such as the non-uniformity, mixing zone, stagnant zones, the propagation of voids, slow flow zone, etc. Moreover, some basic issues on the movement mechanism and characteristics of quasi-static pebble flow are discussed, e.g. the interpretation of force analysis inside the pebble packing, propagation and distribution of voids, formation of equilibrium arches, the effects of stagnant zone on the flow field, and so on. These characteristics of the quasi-static pebble flow are very different from the continuous flow, and the understanding of these characteristics is very helpful for the design and analysis of pebble bed reactors.
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Fox, D. M., and J. S. Lee. "Application of an Arbitrary Lagrangian Eulerian Method to Describe High Velocity Gas-Particle Flow Behavior." In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-03075.
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Novel computational and small-scale experimental investigations were performed in order to better understand the high velocity flow behavior of gas-particle mixtures. The motion of solid objects impacted by the flow of the mixtures was measured by use of high-speed digital video photography. Computations were performed by use of an arbitrary Lagrangian Eulerian (ALE) treatment in a nonlinear finite element code. Constitutive models for description of the solid component of the gas-particle blend were developed based on quasi-statically determined test results. It was observed that there was very close agreement between experimental and computational results and that it was possible to accurately predict the high velocity flow behavior of the gas-particle mixture using quasi-statically determined constitutive models.
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Hussein, Bassam A. "Quasi-experimental method to identify the impact of ambiguity and urgency on project participants in the early project phase." In 2011 IEEE 6th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS). IEEE, 2011. http://dx.doi.org/10.1109/idaacs.2011.6072901.
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Zarei Mahmoudabadi, M., M. Sadighi, and A. Eyvazian. "Theoretical and Experimental Crushing Analysis of Metal Square Honeycombs Under Quasi-Static Loading." In ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2010. http://dx.doi.org/10.1115/esda2010-24739.
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Honeycomb cellular structures, due to their light weight and high energy absorbing, have been used extensively as energy absorbers or cushions to resist external loads. In this paper, the mean crushing stress and the wavelength of the folding mode, as two important parameters in the study of metal square honeycomb crushing under quasi-static loading have been investigated theoretically and experimentally. Firstly, by considering the true cylindrical curvature effects and the flow stress in the folding mode of the honeycomb material, the Wierzbicki’s model in the study of metal hexagonal honeycomb crushing under quasi-static loading is modified. This modification is performed by rewriting the internal energy terms and the external work in the energy method through the basic element folding by considering the true cylindrical curvature effects and the flow stress of the honeycomb material. Comparison of the results obtained by this modified model and Wierzbicki’s model with the experimental data shows better prediction by the model presented in this paper. Subsequently, this modified model has been extended to the study of metal square honeycombs crushing under quasi-static loading and the mean crushing stress and the wavelength of the folding mode of these structures have been predicted. This analytical model predicts the mean crushing stress of the metal square honeycomb as a function of both the geometrical parameters and its material, while the predicted wavelength of the folding mode is just a function of the geometrical parameters. Finally, the experimental tests have been performed to verify the preciseness of this theoretical model.
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Lee, Jong-Min, Yun-Jae Kim, Hyun-Seok Song, and Jin Weon Kim. "Very Low Cycle Fatigue Evaluation of Pipe Elbow and Experimental Validations: I- Quasi-Static Cyclic Loading Test." In ASME 2023 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/pvp2023-106549.
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Abstract In this paper, pipe elbow under cyclic in-plane bending loads was evaluated using strain-based evaluation methods. For strain-based evaluation methods, acceptance criteria for local failure presented in ASME BPVC Sec. VIII and the void growth/shrinkage model were considered. The void growth/shrinkage model is evaluation model that incorporates the void growth effect to the acceptance criteria presented in ASME BPVC Sec. VIII. For the validation of evaluation models, predicted failure cycle of pipe elbow was compared with experimental results. The ASME BPVC Sec. VIII method gives very conservative results. The reason of this conservatism is that the void shrinkage effect under compressive loading is not considered. Therefore, the void growth/shrinkage model incorporating void shrinkage effect significantly improving evaluation results compared to result of ASME BPVC Sec. VIII, and crack initiation cycle can be predicted much closer but still smaller than the experimental result.
Reports on the topic "Quasi-experimental method"
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Maffioli, Alessandro, Pierre Mohnen, Gonzalo Vázquez, and Gustavo Crespi. Evaluating the Impact of Science, Technology and Innovation Programs: a Methodological Toolkit. Inter-American Development Bank, 2011. http://dx.doi.org/10.18235/0008984.
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The purpose of this guideline is to provide ideas and technical advice on how to measure the effectiveness of Science, Technology and Innovation Programs (STIP). The paper addresses the specific challenges of evaluating STIP, from the assessment of the intervention logic to the choice of the most appropriate method to solve the attribution problem. Much attention is devoted to the topic of data, discussing pros and cons of different data sources, data quality issues, and strategies for data collection. The paper analyzes in detail the potential application of experimental and quasi-experimental methods to STIP.
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Hossain, Sharif, Abdullah Al Mahmud Shohag, Zakaria Hossain, Shongkour Roy, and Ubaidur Rob. Improving acceptability, use, and continuation of IUD in Bangladesh. Population Council, 2023. https://doi.org/10.31899/sbsr2024.1042.
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Although the nonhormonal copper intra-uterine device (IUD) is the safest and cheapest long-acting contraceptive method, its use has been declining day-by-day in Bangladesh. Less than 1% of married women 15-49 years of age who currently use a contraceptive method use an IUD. Researchers conducted a quasi-experimental pre-post-test non-equivalent control group designed study to test a simple intervention intended to increase acceptance, use, and continuation of the IUD among married women of reproductive age (18 to 45 years) in Keraniganj, Savar, and Nawabganj Upazilas (sub-districts) in Bangladesh. The study was conducted in a real-life situation of Union Health and Family Welfare Centers from May 2021 to September 2023. This report summarizes the findings from the intervention study.
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Vonk, Jaynie. Sustainable Water and Sanitation in Sierra Leone: Impact evaluation of the ‘Improved WASH Services in WAU and WAR Districts’ project. Oxfam GB, 2022. http://dx.doi.org/10.21201/2021.8401.
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Between October 2016 and March 2019, the Freetown WASH Consortium, led by Oxfam with Against Hunger, Concern Worldwide and Save the Children as members, carried out the 'Improved WASH Services in Western Area Urban (WAU) and Western Area Rural (WAR) Districts' project. Broadly, the project aimed to improve the availability, accessibility, affordability and sustainability of integrated water, sanitation and hygiene (WASH) services, in alignment with the Government of Sierra Leone's national agenda on Ebola recovery and increased preparedness against possible future outbreaks. This Effectiveness Review evaluates the success of this project to increase the sustainability of water and sanitation systems and services. Using a quasi-experimental, mixed method evaluation design, impact is assessed among individuals, households and communities in intervention and comparison areas. Community-level factors contributing to better individual- and household-level outcomes are explored. Find out more by reading the full report now.
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Carvalho, Rita, João Tavares, and Liliana Sousa. Instruments for assessing loneliness in older people in Portugal: a Scoping Review protocol. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, 2021. http://dx.doi.org/10.37766/inplasy2021.10.0002.
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Review question / Objective: The objective of this scoping review is to map the instruments validate for the Portuguese older population (65+ years old) that assess loneliness; and to identify their psychometric properties and contexts where they have been in use. The questions for this scoping review are: What are the validated instruments for Portugal that assess loneliness in the older individuals? What are the psychometric properties of those instruments? In which contexts were the loneliness assessment instruments used? Eligibility criteria: Participants – This scoping review will consider all studies that included older adults with 65 years and over. Concept – This review will be included studies that assess loneliness or cover loneliness by validated instruments that address different dimensions, including, but not limited to, emotional or social. Context – This scoping review will consider studies that used validated instruments the loneliness in Portuguese older adults including, but not limited to the context of community, intermediate care, long-term care or acute care. Types of sources - This scoping review will consider quantitative and mixed-method studies. In the quantitative designs include experimental, quasi-experimental, observational and analytical observational studies including prospective and retrospective cohort studies, case-control studies, and analytical cross-sectional studies will be considered for inclusion. This review will also consider descriptive observational study designs including case series, individual case reports, and descriptive cross-sectional studies for inclusion.
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Deschenes, Olivier, and Kyle Meng. Quasi-Experimental Methods in Environmental Economics: Opportunities and Challenges. National Bureau of Economic Research, 2018. http://dx.doi.org/10.3386/w24903.
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Teo, Chua Tee, and Khiok Seng Quek. Pedagogical change for training teachers: Adapted flipped classroom approach. National Institute of Education, Nanyang Technological University, Singapore, 2020. https://doi.org/10.32658/10497/23256.
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This pilot quasi-experimental project examines the effectiveness of an adapted flipped classroom approach for the teaching of 2 teacher education courses over a semester of 13 weeks. Both the experimental and control groups would be matched at programme level. The control group would be two comparable classes not using the flipped classroom approach but using the didactic or traditional approach of teaching. The flipped classroom approach is also known as the Thayer Method or the inverted classroom or reverse teaching. It involves interactive student-centred engagement pedagogy with individualised online learning before the course. In the adapted flipped classroom, additional guiding questions and power-point slides would be deployed. Students learn content online through e-worksheets and guided discovery before face-to-face classroom time. Students worked through activities, watched videos, navigate websites, read up on articles and answered questions posed to them in the lesson worksheets. In class, students would share their prior learning with each other and they would be encouraged to ask questions of each other and with the tutor. Concepts, theories, controversies and ambiguities will be discussed with the aid of power-point slides. The students in the control group would receive lectures through power-point slides during class time, and learning activities would be conducted. Students in the control group would have no pre-lesson learning activities. The effectiveness of the flipped classroom lessons will be assessed through newly developed surveys, focus group discussions and semi-structured interviews of participants in the experimental and control groups. Results will be analysed using paired sample t tests, ANCOVA and thematic analyses. Findings will enable the lecturers to review and re-design the flipped classroom lessons and thus make evidence based pedagogical changes for the following semester.
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Feng, Yunwen, Jean-Daniel Jean-Daniel, Hilary Nixon, and Monica Ramirez Ibarra. Battery Electric Vehicles: Travel Characteristics of Early Adopters. Mineta Transportation Institute, 2024. http://dx.doi.org/10.31979/mti.2024.1905.
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Do U.S. households with battery electric vehicles (BEVs) drive less or more than U.S. households with internal combustion engine vehicles (ICEVs)? Answering this question is important to policymakers and transportation planners concerned with reducing vehicle miles traveled and the emissions of greenhouse gases from transportation. So far, this question has not been answered satisfactorily, possibly because of the relatively low number of EVs in the U.S. until recently, but also because of methodological issues. In this paper, we aim to fill this gap by analyzing data from the 2017 National Household Travel Survey (NHTS). We apply propensity score matching (PSM), a quasi-experimental method, to examine the differences in self-reported annual mileage and calculated daily mileage for various trip purposes among households with only BEVs (BEV-only), households with both BEVs and ICEVs (BEV+), and households without BEVs (non-BEV households). Our findings indicate that households with BEVs drive fewer annual miles than non-BEV households, but typically travel no less than they do for daily activities. This apparent discrepancy is likely due to taking fewer longer trips because the public charging infrastructure was still in its infancy in 2017, and its reliability was questionable. As technological progress is helping to overcome current battery limitations, policymakers may consider measures for fostering fast charging technologies while pondering new measures to fund both the charging infrastructure and the road network.
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Raudenbush, Stephen. Hierarchical Linear Models (HLM) and Multilevel Causal Inference. Instats Inc., 2023. http://dx.doi.org/10.61700/6mi8hginiy8rh469.
Full textAbstract:
This seminar introduces you to the theory and practice of multilevel modeling, and the logic of causal inference at multiple levels of analysis. The first day introduces you to two-level and three-level analysis, with an emphasis on how to build and interpret HLMs with a theoretically-rigorous foundation to guide estimation and inference. The second day considers how modern methods of causal inference can be applied to multilevel experimental and quasi-experimental designs. The new updated version of the HLM software will be used to illustrate model building and inference in a hands-on way. An official Instats certificate of completion with Professor Raudenbush is provided at the conclusion of the seminar. The seminar offers 2 ECTS Equivalent points for European PhD students.
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Parsons, Helen M., Hamdi I. Abdi, Victoria A. Nelson, et al. Transitions of Care From Pediatric to Adult Services for Children With Special Healthcare Needs. Agency for Healthcare Research and Quality (AHRQ), 2022. http://dx.doi.org/10.23970/ahrqepccer255.
Full textAbstract:
Objective. To understand the evidence base for care interventions, implementation strategies, and between-provider communication tools among children with special healthcare needs (CSHCN) transitioning from pediatric to adult medical care services. Data sources. We searched Ovid MEDLINE, Ovid Embase, the Cochrane Central trials (CENTRAL) registry, and CINAHL to identify studies through September 10, 2021. We conducted grey literature searches to identify additional resources relevant to contextual questions. Review methods. Using a mixed-studies review approach, we searched for interventions or implementation strategies for transitioning CSHCN from pediatric to adult services. Two investigators screened abstracts and full-text articles of identified references for eligibility. Eligible studies included randomized controlled trials, quasi-experimental observational studies, and mixed-method studies of CSHCN, their families, caregivers, or healthcare providers. We extracted basic study information from all eligible studies and grouped interventions into categories based on disease conditions. We summarized basic study characteristics for included studies and outcomes for studies assessed as low to medium risk of bias using RoB-2. Results. We identified 9,549 unique references, 440 of which represented empirical research; of these, 154 (16 major disease categories) described or examined a care transition intervention with enough detail to potentially be eligible for inclusion in any of the Key Questions. Of these, 96 studies met comparator criteria to undergo risk of bias assessment; however only 9 studies were assessed as low or medium risk of bias and included in our analytic set. Low-strength evidence shows transition clinics may not improve hemoglobin A1C levels either at 12 or 24 months in youth with type 1 diabetes mellitus compared with youth who received usual care. For all other interventions and outcomes, the evidence was insufficient to draw meaningful conclusions because the uncertainty of evidence was too high. Some approaches to addressing barriers include dedicating time and resources to support transition planning, developing a workforce trained to care for the needs of this population, and creating structured processes and tools to facilitate the transition process. No globally accepted definition for effective transition of care from pediatric to adult services for CSHCN exists; definitions are often drawn from principles for transitions, encompassing a broad set of clinical aspects and other factors that influence care outcomes or promote continuity of care. There is also no single measure or set of measures consistently used to evaluate effectiveness of transitions of care. The literature identifies a limited number of available training and other implementation strategies focused on specific clinical specialties in targeted settings. No eligible studies measured the effectiveness of providing linguistically and culturally competent healthcare for CSHCN. Identified transition care training, and care interventions to
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Raudenbush, Stephen. Hierarchical Linear Models (HLM) and Multilevel Causal Inference. Instats Inc., 2022. http://dx.doi.org/10.61700/47nvc1nfj731n469.
Full textAbstract:
This seminar, taught by Professor Raudenbush, will introduce you to the theory and practice of multilevel modeling, and the logic of causal inference at multiple levels of analysis. The first day introduces you to two-level and three-level analysis, with an emphasis on how to build and interpret HLMs with a theoretically-rigorous foundation that will guide estimation and inference. The second day considers how modern methods of causal inference can be applied to multilevel experimental and quasi-experimental designs. The new and substantially updated version of the HLM software will be used to illustrate model building and inference in a hands-on way. All participants will receive a free 60-day trial license to this exciting update to the classic HLM software from Scientific Software International, and a 20% discount on a future purchase of HLM. An official Instats certificate of completion with Professor Raudenbush is provided at the conclusion of the seminar. The seminar offers 2 ECTS Equivalent points for European PhD students.