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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

KLIC作為傾向分數配對平衡診斷之可行性探討 / Using Kullback-Leibler Information Criterion on balancing diagnostics for baseline covariates between treatment groups in propensity-score matched samples

李珮嘉, Li, Pei Chia Unknown Date (has links)
觀察性研究資料中,透過傾向分數的使用,可以使基準變數在實驗與對照兩組間達到某種程度的平衡,並可視同為一隨機試驗,進而進行有效的統計推論。文獻中有關平衡與否的診斷,大多聚焦於平均數與變異數的比較。本文中我們提出使用KLIC(Kullback-Leibler Information Criterion)及KS(Kolmogorov and Simonov)兩種比較分配函數差異的統計量,作為另一種平衡診斷工具的構想,並針對其可行性進行探討與評比。此外,數據顯示KLIC及KS與透過傾向分數配對的成功比例呈現負相關。由於配對成功比例過低將導致後續統計推論結果的侷限性,因此本文也就KLIC及KS作為是否進行配對的一個先行指標之可行性作探討。模擬結果顯示,二者的答案均是肯定的。 / In observational studies, propensity scores are frequently used as tools to balance the distribution of baseline covariates between treated and untreated groups to some extent so that the data could be treated as if they were from a randomized controlled trial (RCT) and causal inferences could thus be made. In the past, balance or not was usually diagnosed in terms of the means and/or the variances. In this study, we proposed using either Kullback-Leibler Information Criterion (KLIC) or Kolmogorov and Simonov (KS) statistic as a diagnostic measure, and evaluated its feasibility. In addition, since low propensity score matching rate decreases the power of the statistical inference and a pilot study showed that the matching rate was negatively correlated with KLIC and KS; thus, we also discussed the possibilities of using KLIC and KS to be pre-indices before implementing propensity score matching. Both considerations appear to be positive through our simulation study.
2

Multistage adaptive testing based on logistic positive exponent model / Teste adaptativo multiestágio baseado no modelo logístico de expoente positivo

Thales Akira Matsumoto Ricarte 08 December 2016 (has links)
The Logistic Positive Exponent (LPE) model from Item Response Theory (IRT) and the Multistage Adaptive Testing (MST) using this model are the focus of this dissertation. For the LPE, item parameter estimations efficiency was studied, it was also analyzed the latent trait estimation for different response patterns to verify the effects it has on guessing and accidental mistakes. The LPE was put in contrast to Rasch, 2 and 3 parameter logistic models to compare the its efficiency. The item parameter estimations were implemented using the Bayesian approach for the Monte Carlo Markov Chain and the Marginal Maximum Likelihood. The latent trait estimation were calculated by the Expected a Posterior method. A goodness of fit analysis were made using the Posterior Predictive model-check method and information statistics. In the MST perspective, the LPE was compared with the Rasch and 2 logistic models. Different tests were constructed using methods that uses optimization functions to select items from a bank. Three functions were chosen to this task: the Fisher and Kullback-Leibler informations and the Continuous Entropy Method. The results were obtained with simulated and real data, the latter was from a general science knowledge test calls General Science test and it was provided by the Educational Testing Service company. Results showed that the LPE might help individuals that made mistakes in earlier stage of the test, especially for easy items. However, the LPE requires a large individual sample and time to estimate the item parameters making it an expensive model. MST based on LPE can be dissolve the impact of accidental mistakes from high performance test takers depending of the item pool available and the way the test is constructed. The optimization function performance vary depending of the situation. / O modelo Logístico de Expoente Positivo (LPE) da Teoria de Resposta ao Item (IRT) e o Teste Adaptativo Multiestágio (MST) sob esse modelo são os focos desta tese. Para o LPE, a eficiência da estimações dos parâmetros dos itens foram estudados, também foi analisado como as estimativas dos parâmetros dos indivíduos foram influenciados por padrões de respostas contendo chutes ou erros acidentais. O LPE foi comparado com os modelos de Rasch, Logístico de 2 e 3 Parâmetros para verificar seu desempenho. A estimação dos parâmetros dos itens foi implementada usando Monte Carlo via cadeias de Markov sob a abordagem Bayesiana e a Máxima Verossimilhança Marginal. As estimações dos traços latentes foram calculadas através do Método da Esperança a Posteriori. A qualidade do ajuste dos modelos foram analisadas usando o método Posterior Predictive model-check e critério de informações. Sob o contexto do MST, o LPE foi comparado com os modelos de Rasch e Logístico de 2 Parâmetro. Os MSTs foram construídos usando diferentes funções de objetivas que selecionaram os itens de bancos para comporem os testes. Três funções foram escolhidas para esse trabalho: As informações de Fisher e Kullback-Leibler e o Continuous Entropy Method. Os resultados para dados simulados e reais foram obtidos, os dados reais eram consituídos de respostas a perguntas sob conhecimento científico de do General Science test que foram fornecidos pela empresa Educational Testing Service. Resultados mostraram que o LPE pode ajudar os indivíduos que cometeram erros acidentais nas primeiras perguntas do teste, especialmente para os itens fáceis. Entretanto, este modelo requer tempo e uma grande quantidade de amostras de indivíduos para calcular as estimativas dos parâmetros dos itens o que o torna um modelo caro. O MST sob o modelo LPE pode diminuir o impacto de erros acidentais cometidos por examinandos com alto desempenho dependendo dos itens disponíveis no banco e a forma de construção do MST. O desempenho das funções objetivas variaram de acordo com cada situação.
3

Multistage adaptive testing based on logistic positive exponent model / Teste adaptativo multiestágio baseado no modelo logístico de expoente positivo

Ricarte, Thales Akira Matsumoto 08 December 2016 (has links)
The Logistic Positive Exponent (LPE) model from Item Response Theory (IRT) and the Multistage Adaptive Testing (MST) using this model are the focus of this dissertation. For the LPE, item parameter estimations efficiency was studied, it was also analyzed the latent trait estimation for different response patterns to verify the effects it has on guessing and accidental mistakes. The LPE was put in contrast to Rasch, 2 and 3 parameter logistic models to compare the its efficiency. The item parameter estimations were implemented using the Bayesian approach for the Monte Carlo Markov Chain and the Marginal Maximum Likelihood. The latent trait estimation were calculated by the Expected a Posterior method. A goodness of fit analysis were made using the Posterior Predictive model-check method and information statistics. In the MST perspective, the LPE was compared with the Rasch and 2 logistic models. Different tests were constructed using methods that uses optimization functions to select items from a bank. Three functions were chosen to this task: the Fisher and Kullback-Leibler informations and the Continuous Entropy Method. The results were obtained with simulated and real data, the latter was from a general science knowledge test calls General Science test and it was provided by the Educational Testing Service company. Results showed that the LPE might help individuals that made mistakes in earlier stage of the test, especially for easy items. However, the LPE requires a large individual sample and time to estimate the item parameters making it an expensive model. MST based on LPE can be dissolve the impact of accidental mistakes from high performance test takers depending of the item pool available and the way the test is constructed. The optimization function performance vary depending of the situation. / O modelo Logístico de Expoente Positivo (LPE) da Teoria de Resposta ao Item (IRT) e o Teste Adaptativo Multiestágio (MST) sob esse modelo são os focos desta tese. Para o LPE, a eficiência da estimações dos parâmetros dos itens foram estudados, também foi analisado como as estimativas dos parâmetros dos indivíduos foram influenciados por padrões de respostas contendo chutes ou erros acidentais. O LPE foi comparado com os modelos de Rasch, Logístico de 2 e 3 Parâmetros para verificar seu desempenho. A estimação dos parâmetros dos itens foi implementada usando Monte Carlo via cadeias de Markov sob a abordagem Bayesiana e a Máxima Verossimilhança Marginal. As estimações dos traços latentes foram calculadas através do Método da Esperança a Posteriori. A qualidade do ajuste dos modelos foram analisadas usando o método Posterior Predictive model-check e critério de informações. Sob o contexto do MST, o LPE foi comparado com os modelos de Rasch e Logístico de 2 Parâmetro. Os MSTs foram construídos usando diferentes funções de objetivas que selecionaram os itens de bancos para comporem os testes. Três funções foram escolhidas para esse trabalho: As informações de Fisher e Kullback-Leibler e o Continuous Entropy Method. Os resultados para dados simulados e reais foram obtidos, os dados reais eram consituídos de respostas a perguntas sob conhecimento científico de do General Science test que foram fornecidos pela empresa Educational Testing Service. Resultados mostraram que o LPE pode ajudar os indivíduos que cometeram erros acidentais nas primeiras perguntas do teste, especialmente para os itens fáceis. Entretanto, este modelo requer tempo e uma grande quantidade de amostras de indivíduos para calcular as estimativas dos parâmetros dos itens o que o torna um modelo caro. O MST sob o modelo LPE pode diminuir o impacto de erros acidentais cometidos por examinandos com alto desempenho dependendo dos itens disponíveis no banco e a forma de construção do MST. O desempenho das funções objetivas variaram de acordo com cada situação.

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