Thesis advisor: Laura M. O'Dwyer / The purpose of this study was to determine which of three competing models will provide, reliable, interpretable, and responsive measures of elementary students' understanding of the nature of science (NOS). The Nature of Science Instrument-Elementary (NOSI-E), a 28-item Rasch-based instrument, was used to assess students' NOS understanding. The NOS construct was conceptualized using five construct dimensions (Empirical, Inventive, Theory-laden, Certainty and Socially & Culturally Embedded). The competing models represent three internal models for the NOS construct. One postulate is that the NOS construct is unidimensional where one latent construct explains the relationship between the 28 items of the NOSI-E. Alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. A validity argument was developed that hypothesized that the internal structure of the NOS construct is best represented by the multidimensional Rasch model. Four sets of analyses were performed in which the three representations were compared. These analyses addressed five validity aspects (content, substantive, generalizability, structural and external) of construct validity. The vast body of evidence supported the claim that the NOS construct is composed of five separate but inter-related dimensions that is best represented by the multidimensional Rasch model. The results of the multidimensional analyses indicated that the items of the five subscales were of excellent technical quality, exhibited no differential item functioning (based on gender), had an item hierarchy that conformed to theoretical expectations; and together formed subscales of reasonable reliability (> 0.7 on each subscale) that were responsive to change in the construct Theory-laden scores from the multidimensional model predicted students' science achievement with scores from all five NOS dimensions significantly predicting students' perceptions of the constructivist nature of their classroom learning environment. The NOSI-E instrument is a theoretically grounded scale that can measure elementary students' NOS understanding and appears suitable for use in science education research. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement, and Evaluation.

Made available in DSpace on 2015-05-14T12:56:00Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 12440507 bytes, checksum: 4c602610a4947af78ebd9048d453e0e8 (MD5) Previous issue date: 2004-09-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study had two objectives. The main objective was to evaluate the association of the impact of temporomandibular disorders (TMD) on oral health related quality of life to the psychosocial and psychological factors. The specific objective was to validate the Portuguese version of Axis II questionnaire to Research Diagnostic Criteria for TMD (RDC/TMD) as preconized by Dworkin and LeResche at 1992. The sample was compounded by 156 patients, with TMD, who attempted at Orofacial Pain Control Center School of Dentistry of Pernambuco University, from July 2003 to February 2004. Data collection was done by the author using the following instruments: Simplified Anamnesis Index DMF for screening patients with TMD; RDC/TMD Axis I to evaluated clinically and to classify TMD and Axis II to evaluate psychosocial and psychological factors; the specific questionnaires to evaluated oral health related to quality of life, OIDP and OHIP-14. Two different types of studies were conducted: validation study and cross sectional study. The validation study consisted on the evaluation of internal consistence by alpha Crombach reliability test; reliability and reproducibility estimated by Kappa statistics and by Spearman correlation and also concurrent validity (Spearman). For the transversal study, one has used Kruskall Wallis to test OIDP and ANOVA to test OHIP-14. The Portuguese version for Axis II of RDC/TMD was considered consistent (Crombach a=0,72), reliable (Kappa 0,73-0,91; p<0,01) and valid (p<0,01). According to transversal study, among the variables for sample characterization, the impact on oral health related qualify of life was statistical associated to sex and scholarship, this factor exclusively for OHIP-14. On Axis I, using OIDP, the impact was associated to groups I and II, muscle and joint disorders, respectively. While for OHIP-14, only for group I (muscle disorders) the association was detected. On Axis II, psychological factors, as depression and somatization (inespecific organic symptoms with or without pain) and psychosocial factor of disability and pain were statically associated to the impact of oral health related quality of life, according to evaluation with OIDP and OHIP-14. The validity of Axis II of RDC/TMD followed the methodology proposed at the literature and showed reproducbility and validity for brazilian population. Temporomandibular disorders and psychosocial and psychological factors produced an important impact on oral health related quality of life, associated to psychosocial and psychological factors associated and proportional to their intensity. / O presente estudo teve dois objetivos. O objetivo geral foi avaliar a associação entre o impacto da disfunção temporomandibular (DTM) na qualidade de vida relacionada à saúde bucal, e os fatores psicossocial e psicológicos. O objetivo específico foi realizar a validação da versão em português do questionário Eixo II dos Critérios Diagnósticos de Pesquisa em DTM (RDC/TMD), preconizado por Dworkin e LeResche, em 1992. A amostra foi composta por 155 pacientes portadores de DTM que procuraram atendimento no Centro de Controle da Dor Orofacial da Faculdade de Odontologia da Universidade de Pernambuco no período de Julho de 2003 a Fevereiro de 2004. Para a coleta de dados foram utilizados os seguintes instrumentos: Índice Anamnésico Simplificado DMF para a triagem dos pacientes com DTM; RDC/TMD: Eixo I para avaliação clínica e classificação da DTM, e Eixo II para avaliação psicossocial e psicológica e os questionários específicos para avaliação da qualidade de vida relacionada à saúde bucal OIDP e OHIP-14. Foram realizados dois tipos de estudo: estudo de validação e transversal. O estudo de validação constou da avaliação da consistência interna pelo teste de confiabilidade alfa Crombach; confiabilidade e reprodutibilidade, estimada pela estatística Kappa e correlação de Spearman e validação concorrente (Spearman). No estudo transversal, para o OIDP, utilizouse o teste Kruskal-Wallis e para o OHIP-14 o teste ANOVA. Os resultados revelaram que a versão em português Eixo II do RDC/TMD foi considerada consistente (Crombach=0,72); reprodutível (Kappa 0,73-0,91; p<0,01) e válida (p<0,01). No estudo transversal, dentre as variáveis de caracterização amostral, o impacto da qualidade de vida relacionado à saúde bucal foi estatisticamente associado com gênero e escolaridade, sendo este último fator apenas evidenciado quando da utilização do OHIP-14. No Eixo I, usando o OIDP, o impacto teve associação com os grupos I e III, de desordem muscular e articular, respectivamente; com o OHIP-14, teve associação apenas para o grupo I (desordem muscular). No Eixo II, os fatores psicológicos, como depressão e somatização (sintomas físicos não específicos, com e sem itens de dor), e o fator psicossocial de incapacidade e intensidade da dor, foram estatisticamente associados ao impacto da qualidade de vida relacionado à saúde bucal, quando avaliados pelo OIDP e OHIP-14. Conclui-se que a validação do Eixo II do RDC/TMD seguiu metodologia proposta na literatura e mostrou-se reprodutível e válida para a população brasileira. A disfunção temporomandibular e os fatores psicossocial e psicológicos produzem importante impacto nos portadores de DTM, interferindo negativamente na qualidade de vida relacionada à saúde bucal, e este impacto também foi associado ao grau de severidade dos fatores psicossocial e psicológicos.

Randomized controlled trials (RCTs) are the hallmark of evidence-based medicine and form the basis for translating research data into clinical practice. This review summarizes commonly applied designs and quality indicators of RCTs to provide guidance in interpreting and critically evaluating clinical research data. It further reflects on the principle of equipoise and its practical applicability to clinical science with an emphasis on critical care and neurological research. We performed a review of educational material, review articles, methodological studies, and published clinical trials using the databases MEDLINE, PubMed, and ClinicalTrials.gov. The most relevant recommendations regarding design, conduction, and reporting of RCTs may include the following: 1) clinically relevant end points should be defined a priori, and an unbiased analysis and report of the study results should be warranted, 2) both significant and nonsignificant results should be objectively reported and published, 3) structured study design and performance as indicated in the Consolidated Standards of Reporting Trials statement should be employed as well as registration in a public trial database, 4) potential conflicts of interest and funding sources should be disclaimed in study report or publication, and 5) in the comparison of experimental treatment with standard care, preplanned interim analyses during an ongoing RCT can aid in maintaining clinical equipoise by assessing benefit, harm, or futility, thus allowing decision on continuation or termination of the trial.

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