869 resultados para item response theory


Relevância:

100.00% 100.00%

Publicador:

Resumo:

It is important to check the fundamental assumption of most popular Item Response Theory models, unidimensionality. However, it is hard for educational and psychological tests to be strictly unidimensional. The tests studied in this paper are from a standardized high-stake testing program. They feature potential multidimensionality by presenting various item types and item sets. Confirmatory factor analyses with one-factor and bifactor models, and based on both linear structural equation modeling approach and nonlinear IRT approach were conducted. The competing models were compared and the implications of the bifactor model for checking essential unidimensionality were discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

It is well accepted that tumorigenesis is a multi-step procedure involving aberrant functioning of genes regulating cell proliferation, differentiation, apoptosis, genome stability, angiogenesis and motility. To obtain a full understanding of tumorigenesis, it is necessary to collect information on all aspects of cell activity. Recent advances in high throughput technologies allow biologists to generate massive amounts of data, more than might have been imagined decades ago. These advances have made it possible to launch comprehensive projects such as (TCGA) and (ICGC) which systematically characterize the molecular fingerprints of cancer cells using gene expression, methylation, copy number, microRNA and SNP microarrays as well as next generation sequencing assays interrogating somatic mutation, insertion, deletion, translocation and structural rearrangements. Given the massive amount of data, a major challenge is to integrate information from multiple sources and formulate testable hypotheses. This thesis focuses on developing methodologies for integrative analyses of genomic assays profiled on the same set of samples. We have developed several novel methods for integrative biomarker identification and cancer classification. We introduce a regression-based approach to identify biomarkers predictive to therapy response or survival by integrating multiple assays including gene expression, methylation and copy number data through penalized regression. To identify key cancer-specific genes accounting for multiple mechanisms of regulation, we have developed the integIRTy software that provides robust and reliable inferences about gene alteration by automatically adjusting for sample heterogeneity as well as technical artifacts using Item Response Theory. To cope with the increasing need for accurate cancer diagnosis and individualized therapy, we have developed a robust and powerful algorithm called SIBER to systematically identify bimodally expressed genes using next generation RNAseq data. We have shown that prediction models built from these bimodal genes have the same accuracy as models built from all genes. Further, prediction models with dichotomized gene expression measurements based on their bimodal shapes still perform well. The effectiveness of outcome prediction using discretized signals paves the road for more accurate and interpretable cancer classification by integrating signals from multiple sources.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The purpose of this study was to investigate how university students perceive their involvement in the cyberbullying phenomenon, and its impact on their well-being. Thus, this study presents a preliminary approach of how college students’ perceived involvement in acts of cyberbullying can be measured. Firstly, Exploratory Factor Analysis (N = 349) revealed a unidimensional structure of the four scales included in the Cyberbullying Inventory for College Students. Then, Item Response Theory (N = 170) was used to analyze the unidimensionality of each scale and the interactions between participants and items. Results revealed good item reliability and Cronbach’s α for each scale. Results also showed the potential of the instrument and how college students underrated their involvement in acts of cyberbullying. Additionally, aggression types, coping strategies and sources of help to deal with cyberbullying were identified and discussed. Lastly, age, gender and course-related issues were considered in the analysis. Implications for researchers and practitioners are discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

2000 Mathematics Subject Classification: 91E45.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

2010 Mathematics Subject Classification: 62P15.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Formal education, understood by the gradual process that occurs at school, aims at learning and systematic knowledge is of great interest to society as it benefits its individuals and leads to many positive effects, such as increased productivity and welfare (Johnes, Johnes, 2007). Understanding what influences the educational outcome is as important as the result itself, because lets you manage these variables in order to obtain a better student performance. This work uses the data envelopment analysis (DEA) to compare the efficiency of Rio Grande do Norte schools. In this nonparametric method, an efficiency frontier was construct from the best schools that use the inputs set to generate educational products. Therefore, the data used were obtain by Test Brazil and year 2011 School Census to state and municipal schools of Rio Grande do Norte. Some of the variables considered as inputs and outputs have been obtain directly these bases - the other two were prepared, using the Item Response Theory (IRT) - they are the socioeconomic and school infrastructure indices. As a first step, we compared several DEA models, with changes of input variables. Then was chose the non-discretionary model for which was deep the analysis of results. The results showed that only seven schools were efficient in the 5th and 9th grades simultaneously; there were no significant differences between the efficiency of municipal and state schools; and there were no differences between large and small schools. Analyzing the municipalities, Mossoró excelled in both years with the highest proportion of efficient schools. Finally, the study suggests that using the projections provided by the DEA method, the most inefficient schools would be able to achieve the goal IDEB in 2011, in other words, it is possible to improve the education of significant state taking the efficient schools as a basis for too much.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In 2004, the National Institutes of Health made available the Patient-Reported Outcomes Measurement Information System – PROMIS®, which is constituted of innovative item banks for health assessment. It is based on classical, reliable Patient-Reported Outcomes (PROs) and includes advanced statistical methods, such as Item Response Theory and Computerized Adaptive Test. One of PROMIS® Domain Frameworks is the Physical Function, whose item bank need to be translated and culturally adapted so it can be used in Portuguese speaking countries. This work aimed to translate and culturally adapt the PROMIS® Physical Function item bank into Portuguese. FACIT (Functional Assessment of Chronic Illness Therapy) translation methodology, which is constituted of eight stages for translation and cultural adaptation, was used. Fifty subjects above the age of 18 years participated in the pre-test (seventh stage). The questionnaire was answered by the participants (self-reported questionnaires) by using think aloud protocol, and cognitive and retrospective interviews. In FACIT methodology, adaptations can be done since the beginning of the translation and cultural adaption process, ensuring semantic, conceptual, cultural, and operational equivalences of the Physical Function Domain. During the pre-test, 24% of the subjects had difficulties understanding the items, 22% of the subjects suggested changes to improve understanding. The terms and concepts of the items were totally understood (100%) in 87% of the items. Only four items had less than 80% of understanding; for this reason, it was necessary to chance them so they could have correspondence with the original item and be understood by the subjects, after retesting. The process of translation and cultural adaptation of the PROMIS® Physical Function item bank into Portuguese was successful. This version of the assessment tool must have its psychometric properties validated before being made available for clinical use.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Les délinquants sexuels sadiques sont généralement décrits comme une entité clinique particulière commettant des délits graves. Or, la notion même de sadisme sexuel pose un nombre important de problèmes. Parmi ceux-ci, on retrouve des problèmes de validité et de fidélité. Perçu comme une maladie dont on est atteint ou pas, le sadisme a été étudié comme si les sadiques étaient fondamentalement différents. À l’heure actuelle, plusieurs travaux laissent croire que la majorité des troubles psychologiques se présentent comme une différence d'intensité (dimension) plutôt qu’une différence de nature (taxon). Même si la conception médicale prévaut encore en ce qui concerne le sadisme sexuel, plusieurs évoquent l’idée qu’il pourrait être mieux conceptualisé à l’aide d’une approche dimensionnelle. En parallèle, nos connaissances sur les facteurs contributifs au développement du sadisme sexuel sont limitées et reposent sur de faibles appuis empiriques. Jusqu'à présent, très peu d'études se sont intéressées aux facteurs menant au développement du sadisme sexuel et encore moins ont tenté de valider leurs théories. En outre, nos connaissances proviennent majoritairement d'études de cas portant sur les meurtriers sexuels, un sous-groupe très particulier de délinquants fréquemment motivé par des intérêts sexuels sadiques. À notre connaissance, aucune étude n'a proposé jusqu'à présent de modèle développemental portant spécifiquement sur le sadisme sexuel. Pourtant, l'identification de facteurs liés au développement du sadisme sexuel est essentielle dans notre compréhension ainsi que dans l'élaboration de stratégie d'intervention efficace. La présente thèse s'inscrit dans un contexte visant à clarifier le concept de sadisme sexuel. Plus spécialement, nous nous intéressons à sa structure latente, à sa mesure et à ses origines développementales. À partir d'un échantillon de 514 délinquants sexuels évalué au Massachusetts Treatment Center, la viabilité d’une conception dimensionnelle du sadisme sexuel sera mise à l’épreuve à l'aide d'analyses taxométriques permettant d'étudier la structure latente d'un construit. Dans une seconde étape, à l'aide d'analyses de Rasch et d'analyses appartenant aux théories de la réponse à l'item à deux paramètres, nous développerons la MTC Sadism Scale (MTCSS), une mesure dimensionnelle du sadisme sexuel. Dans une troisième et dernière étape, un modèle développemental sera élaboré à l'aide d'équations structurales. La présente thèse permettra de contribuer à la clarification du concept de sadisme sexuel. Une clarification de la structure latente et des facteurs développementaux permettra de saisir les devis de recherche les plus à même de capturer les aspects essentiels. En outre, ceci permettra d'identifier les facteurs pour lesquels une intervention est la plus appropriée pour réduire la récidive, ou la gravité de celle-ci.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Thesis (Ph.D.)--University of Washington, 2016-08

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Relational reasoning, or the ability to identify meaningful patterns within any stream of information, is a fundamental cognitive ability associated with academic success across a variety of domains of learning and levels of schooling. However, the measurement of this construct has been historically problematic. For example, while the construct is typically described as multidimensional—including the identification of multiple types of higher-order patterns—it is most often measured in terms of a single type of pattern: analogy. For that reason, the Test of Relational Reasoning (TORR) was conceived and developed to include three other types of patterns that appear to be meaningful in the educational context: anomaly, antinomy, and antithesis. Moreover, as a way to focus on fluid relational reasoning ability, the TORR was developed to include, except for the directions, entirely visuo-spatial stimuli, which were designed to be as novel as possible for the participant. By focusing on fluid intellectual processing, the TORR was also developed to be fairly administered to undergraduate students—regardless of the particular gender, language, and ethnic groups they belong to. However, although some psychometric investigations of the TORR have been conducted, its actual fairness across those demographic groups has yet to be empirically demonstrated. Therefore, a systematic investigation of differential-item-functioning (DIF) across demographic groups on TORR items was conducted. A large (N = 1,379) sample, representative of the University of Maryland on key demographic variables, was collected, and the resulting data was analyzed using a multi-group, multidimensional item-response theory model comparison procedure. Using this procedure, no significant DIF was found on any of the TORR items across any of the demographic groups of interest. This null finding is interpreted as evidence of the cultural-fairness of the TORR, and potential test-development choices that may have contributed to that cultural-fairness are discussed. For example, the choice to make the TORR an untimed measure, to use novel stimuli, and to avoid stereotype threat in test administration, may have contributed to its cultural-fairness. Future steps for psychometric research on the TORR, and substantive research utilizing the TORR, are also presented and discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this article, the change in examinee effort during an assessment, which we will refer to as persistence, is modeled as an effect of item position. A multilevel extension is proposed to analyze hierarchically structured data and decompose the individual differences in persistence. Data from the 2009 Program of International Student Achievement (PISA) reading assessment from N = 467,819 students from 65 countries are analyzed with the proposed model, and the results are compared across countries. A decrease in examinee effort during the PISA reading assessment was found consistently across countries, with individual differences within and between schools. Both the decrease and the individual differences are more pronounced in lower performing countries. Within schools, persistence is slightly negatively correlated with reading ability; but at the school level, this correlation is positive in most countries. The results of our analyses indicate that it is important to model and control examinee effort in low-stakes assessments. (DIPF/Orig.)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Instituto de Física, Programa de Pós-Graduação de Mestrado Profissional em Ensino de Física, Mestrado Nacional Profissional em Ensino de Física, 2015.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Estatística, Programa de Pós-Graduação em Estatística, 2015.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Les délinquants sexuels sadiques sont généralement décrits comme une entité clinique particulière commettant des délits graves. Or, la notion même de sadisme sexuel pose un nombre important de problèmes. Parmi ceux-ci, on retrouve des problèmes de validité et de fidélité. Perçu comme une maladie dont on est atteint ou pas, le sadisme a été étudié comme si les sadiques étaient fondamentalement différents. À l’heure actuelle, plusieurs travaux laissent croire que la majorité des troubles psychologiques se présentent comme une différence d'intensité (dimension) plutôt qu’une différence de nature (taxon). Même si la conception médicale prévaut encore en ce qui concerne le sadisme sexuel, plusieurs évoquent l’idée qu’il pourrait être mieux conceptualisé à l’aide d’une approche dimensionnelle. En parallèle, nos connaissances sur les facteurs contributifs au développement du sadisme sexuel sont limitées et reposent sur de faibles appuis empiriques. Jusqu'à présent, très peu d'études se sont intéressées aux facteurs menant au développement du sadisme sexuel et encore moins ont tenté de valider leurs théories. En outre, nos connaissances proviennent majoritairement d'études de cas portant sur les meurtriers sexuels, un sous-groupe très particulier de délinquants fréquemment motivé par des intérêts sexuels sadiques. À notre connaissance, aucune étude n'a proposé jusqu'à présent de modèle développemental portant spécifiquement sur le sadisme sexuel. Pourtant, l'identification de facteurs liés au développement du sadisme sexuel est essentielle dans notre compréhension ainsi que dans l'élaboration de stratégie d'intervention efficace. La présente thèse s'inscrit dans un contexte visant à clarifier le concept de sadisme sexuel. Plus spécialement, nous nous intéressons à sa structure latente, à sa mesure et à ses origines développementales. À partir d'un échantillon de 514 délinquants sexuels évalué au Massachusetts Treatment Center, la viabilité d’une conception dimensionnelle du sadisme sexuel sera mise à l’épreuve à l'aide d'analyses taxométriques permettant d'étudier la structure latente d'un construit. Dans une seconde étape, à l'aide d'analyses de Rasch et d'analyses appartenant aux théories de la réponse à l'item à deux paramètres, nous développerons la MTC Sadism Scale (MTCSS), une mesure dimensionnelle du sadisme sexuel. Dans une troisième et dernière étape, un modèle développemental sera élaboré à l'aide d'équations structurales. La présente thèse permettra de contribuer à la clarification du concept de sadisme sexuel. Une clarification de la structure latente et des facteurs développementaux permettra de saisir les devis de recherche les plus à même de capturer les aspects essentiels. En outre, ceci permettra d'identifier les facteurs pour lesquels une intervention est la plus appropriée pour réduire la récidive, ou la gravité de celle-ci.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This thesis examined factors influencing health professional's response to victims of domestic violence in Vietnam. As this is the first time that this type of research has been conducted in Vietnam, it was expected that the results would contribute significantly to local knowledge and should add to global perspectives. Since it is the first questionnaire about this topic to be developed in Vietnam, the psychometric property of the questionnaire was primarily established, resulting in the questionnaire being recommended to use for further study. By explaining the factors that affect the intentions to respond of health workers, this project provides key data for authorities to design intervention strategies to improve the responses of health professionals to victims of domestic violence in Vietnam.