The purpose of this study was to determine if using a multistage approach for the empirical selection of anchor items would lead to more accurate DIF detection rates than the anchor selection methods proposed by Kopf, Zeileis, & Strobl (2015b). A simulation study was conducted in which the sample size, percentage of DIF, and balance of DIF were manipulated. The outcomes of interest were true positive rates, false positive rates, familywise false positive rates, anchor contamination rates, and familywise anchor contamination rates. Results showed the proposed multistage methods produced lower anchor contamination rates than the non-multistage methods under some conditions, but there were generally no meaningful differences in true positive and false positive rates.

No description available.

Although the overall quantity of international research has increased, existent studies tend to adopt an instrument developed in one culture to use in the other, leading to measurement bias. In addition, previous cross-cultural research mainly focuses on comparisons between collectivist and individualistic backgrounds (e.g., American vs. Chinese) without considering the similarities and differences within the collectivist societies (e.g., China vs. Mexico). This dissertation project has two purposes, with Study 1 aiming to examine measurement equivalence of two widely used instruments while Study 2 investigating if an attachment-based two-serial mediation model remained constant among three cross-cultural samples collected from the US, Mexico, and China. A total of 1211 participants, including 360 American university students, 441 Mexican students, and 410 Chinese students participated in the study. Differential item functioning (DIF) in lordif package in R and structural equation modeling (SEM) in Mplus 8.1 were adopted for Study 1 and 2, respectively. The results of Study 1 indicated the proposed instruments were culturally invariant in English, Spanish, and Chinese with some modifications. Study 2 showed that assertiveness/self-conscious emotions mediated the association between adult attachment and depression/aggression only in the US group. However, the two-serial mediation model in which the link between adult attachment and depression/aggression via assertiveness to self-conscious emotions was supported in Mexican and Chinese groups, not in the US group. Findings from these two cross-cultural adult attachment studies provide additional insights for future attachment research and useful implications for psychologists working with diverse individuals from the US, Mexico, and China.

Multilingualism in the classroom is one of the many challenges found in the cumbersome bag that the South African education system is carrying over its shoulders at present. Globalisation and migration have added to the burden as factors adding further diversity to the already diverse classroom. In South Africa the spotlight is focused on equality. Equality is expected in the education system, and in the classroom and especially in tests. With 11 official languages excluding the additional languages from foreign learners it has become a daunting task to create tests that are fair across multilingual learners in one classroom. Items in tests that function differently from one group to another can provide biased marks. An investigation was done in order to detect any biased items present in a Picture Vocabulary Test. The study was lead by the main research question being: How do objects used in a Picture Vocabulary Test influence the level of validity? The first sub research question was: How do objects used in a Picture Vocabulary Test influence the level of validity? The next sub question was: To what extent is an undimensional trait measured by a Picture Vocabulary Test? The final subquestion was To what extent do the items in a Picture Vocabulary Test perform the same for the different language groups? This Picture Vocabulary Test was administered to Grade 1 learners in Afrikaans, English or Sepedi speaking schools within Pretoria, Gauteng. The sample totalling 1361 learners. The process involved a statistical procedure known as Rasch analyses. With the help of Rasch a Differential Item Functioning (DIF) analysis was done to investigate whether biased items were present in the test. The aim of this study it is to create greater awareness as to how biased items in tests can be detected and resolved. The results showed that the items in the Picture Vocabulary Test all tested vocabulary. Although items were detected that did indeed perform differently across the three language groups participating in the study. / Dissertation (MEd)--University of Pretoria, 2010. / Science, Mathematics and Technology Education / unrestricted

No description available.

Myxococcus xanthus Dif proteins are chemotaxis homologues that regulate exopolysaccharide (EPS) biogenesis. Previous genetic studies suggested that Dif protein might interact with one another as do the chemotaxis proteins in enterics. The interactions among Dif proteins were since investigated with the yeast two-hybrid (Y2H) system. The results indicate that DifC interacts with both DifA and DifE. Using a modified Y2H system, DifC was shown to be able to bring DifA and DifE into a protein complex. Further Y2H experiments demonstrated that the different conserved domains of DifE likely function as their counterparts of CheA-type kinases because the putative P2 domain of DifE interacts with DifD, P5 with DifC and the dimerization domain P3 with itself. Similarly, DifA can interact with itself through its C-terminal region. In addition, DifG was found to interact with the CheY homologue DifD. These findings support the notion that Dif proteins constitute a unique chemotaxis-like signal transduction pathway in M. xanthus. In addition, KapB, a TPR (Tetratricopeptide repeats) protein, was identified as an interacting partner of DifE byY2H library screening. Further analysis demonstrated that the N-terminal half of KapB interacted with the putative P2 domain of DifE. KapB had been previously reported to interact with several Serine/Threonine (Ser/Thr) kinase pathways including the Pkn4-Pfk pathway. This pathway is implicated in glycogen metabolism in M. xanthus by a previous report. In this study, kapB as well as pfkn deletion mutants were found to overproduce EPS. It was also found that the Dif pathway is involved in glycogen metabolism because the glycogen level is altered in dif mutants. These results indicate EPS biogenesis and glycogen metabolism may be coordinately regulated. This coordination of the Dif-regulated EPS production and the Pkn4-regulated glycogen metabolism appears to involve KapB. This is the first example of a TPR protein mediating the interplays of a histidine kinase pathway and a Ser/Thr kinase pathway. / Master of Science

Esta tese tem por objetivo o desenvolvimento de metodologias eficientes e de baixo custo para ajustar as propriedades elétricas de OFETs de canal p e de canal n, a fim de possibilitar a fabricação do circuito complementar orgânico, semelhante a uma estrutura CMOS. O desempenho do circuito complementar fabricado foi otimizado, e também foi confeccionado por impressão um OFETs de canal operando em baixas tensões. Para a fabricação do CMOS orgânico foi proposto um método baseado na seleção adequada do solvente da camada dielétrica para ajustar o desempenho elétrico dos OFETs de canal p e de canal n. Os solventes, MEK, nBA e DMSO foram selecionados para a dissolução do PMMA por apresentarem diferenças nos valores de momento de dipolo, de ponto de ebulição e de graus de ortogonalidade em relação as camadas semicondutoras de P3HT e de P(NDI2OD-T2) dos OFETs. A análise dos resultados dos OFETs de canal p e de canal n demonstrou que a metodologia proposta é adequada tanto para o ajuste das propriedades elétricas destes dispositivos quanto para a otimização do desempenho dos mesmos. Os melhores desempenhos elétricos para os OFETs de canal p e de canal n foram obtidos quando utilizados o DMSO e o MEK como solventes do PMMA, respectivamente, devido à perfeita ortogonalidade destes solventes em relação às camadas semicondutoras. Os OFETs de canal p que utilizaram o DMSO e os OFETs de canal n que utilizaram o nBA foram os que apresentaram desempenhos elétricos semelhantes, sendo portanto aplicados na fabricação do CMOS. Valores de ganho entre 6,8 e 7,8 e de margem de ruído entre 28,3 V e 34,5 V foram obtidos para inversores complementares fabricados nesta etapa do trabalho. OFETs de canal p utilizando uma blenda de PTAA: diF TES ADT como camada semicondutora, o PEDOT:PSS como eletrodos dreno/fonte e o P(VDF-TrFE-CFE) como camada dielétrica também foram fabricados neste trabalho. A técnica de blade-coating foi utilizada para a deposição dos eletrodos dreno/fonte e da camada semicondutora, ao passo que a técnica de spray-coating foi utilizada para a deposição da camada dielétrica. Da análise dos resultados foi possível inferir que a utilização de um dielétrico com elevada constante dielétrica (K), como o P(VDF-TrFE-CFE), possibilita o funcionamento dos transistores a baixas tensões (≤ 8 V), porém com valores de mobilidade reduzidos devido à elevada desordem dipolar na interface provocada por este dielétrico. Para minimizar esses efeitos, uma fina camada de um polímero fluorado foi depositada entre a camada semicondutora e a dielétrica pela técnica de blade-coating, constituindo assim uma bicamada dielétrica nos OFETs. Dos resultados das medidas elétricas dos OFETs constituídos pela bicamada dielétrica foi observada permanência do funcionamento destes dispositivos a tensões inferiores a 8 V com desempenho elétricos superiores a resultados já publicados na literatura. Por fim, inversores lógicos unipolares com transistores de carga foram fabricados com os OFETs que utilizaram a bicamada dielétrica, sendo obtidos valores de ganho entre 1,2 e 1,6 e de margem de ruído entre 56% e 68,5% de ½ VDD. / This thesis aimed to develop an efficient and low cost method to adjust the electrical properties of p- and n-channel OFETs to allow us to build an organic CMOS and the optimization of printed p-channel OFETs to work at low voltages. We proposed a method to fabricate the organic CMOS, based on the careful selection of dielectric solvent, which was adjusted to obtain the best performance of p- and n-channel OFETs. The dielectric solvents as MEK, nBA and DMSO were selected to dissolve the PMMA dielectric polymer due their different physical properties as dipole moment and boiling point and because they showed slightly different degrees of orthogonality to the P3HT and P(NDI2OD-T2) semiconductor layers of the OFETs. The results showed that the careful selection of the dielectric solvent not only allows to tune the electrical characteristics of the p- and n-channel OFETs, but also to improve the performance of these devices. The best performances were achieved when DMSO and MEK were used as dielectric solvents of the p and n-channel OFETs, respectively, as result of the perfectly orthogonality of these solvents to the semiconductor layers. P-channel OFETs using DMSO and n-channel OFETs using nBA showed similar electrical characteristics and thus, they were used to construct the organic CMOS. The organic complementary inverters showed high gain and noise margin values in the range of 6,8 to 7,8 and 28,3 V to 34,5 V, respectively. Printed p-channel OFETs were also fabricated, in which the blend PTAA:diF TES ADT was used as semiconductor channel, PEDOT:PSS as the drain/source electrodes and P(VDF-TrFE-CFE) as the dielectric layer. The blade-coating technique was used to deposit the source/drain electrodes and the semiconductor layer, while the spray-coating technique was used to deposit the dielectric layer. It was observed that using high-k dielectric as P(VDF-TrFE-CFE) enable to reduce the operating voltage of the OFETs (≤8 V), however, this high-k dielectric also reduced the field effect mobility due the dipolar disorder at the semiconductor/dielectric interface. To minimize the dipolar issue at the interface, we inserted a thin fluoropolymer dielectric layer by blade-coating between the semiconductor and the high-k dielectric layers, thus constituting a dielectric bilayer on the OFETs. From the electrical measurements of the OFETs with the dielectric bilayer, it was observed that the devices were still working at 8 V and they also showed better performance in comparison to results already published. Finally, organic unipolar inverters with load transistors were fabricated using the p-channel OFETs with the dielectric bilayer and they showed reasonable performance, with gain and noise margin in the range of 1,2 to 1,6 and 56% e 68,5% of ½ VDD, respectively.

Verschiedene Schulleistungsstudien stellten für Kinder mit nicht-deutscher Familiensprache bereits in der Grundschule substanzielle Disparitäten im Bereich Mathematik fest. Diese Disparitäten führten zu der Frage, ob die verwendeten Testverfahren zu hohe sprachliche Hürden für Kinder mit nicht-deutscher Familiensprache aufweisen und daher nicht ausreichend in der Lage sind, die Kompetenzen dieser Gruppe valide zu erfassen. In dieser kumulativen Arbeit wurde geprüft, inwiefern die sprachliche Komplexität von Mathematikaufgaben in der Grundschule einen benachteiligenden Einfluss auf die Erfassung der Mathematikleistung von Kindern mit nicht-deutscher Familiensprache darstellt. Zunächst wurde geprüft, ob die in nationalen Schulleistungsstudien verwendeten Aufgaben für diese Gruppe differenziell valide sind. Daran anschließend wurde untersucht, ob sich itemspezifische Kompetenznachteile durch die sprachlichen Merkmale der Aufgaben erklären lassen. In der vorliegenden Arbeit konnte gezeigt werden, dass die differenzielle Validität der betrachteten Testverfahren für Kinder mit nicht-deutscher Familiensprache insgesamt gering ausgeprägt ist. Ferner wurde festgestellt, dass sich die einzelnen sprachlichen Merkmale der Aufgaben sowohl spezifisch als auch gemeinsam auf die differenzielle Validität auswirken. Der größte Anteil der itemspezifischen Kompetenznachteile wurde durch mehrere Merkmale gemeinsam aufgeklärt. Eine experimentelle Teilstudie zeigte, dass eine sprachliche Vereinfachung nicht geeignet scheint, um die Kompetenznachteile von Kindern mit nicht-deutscher Familiensprache substanziell zu verringern. Ein Vergleich der Effekte sprachlicher Merkmale von Mathematikaufgaben auf die Mathematikleistungen von Kindern mit nicht-deutscher Familiensprache zwischen der dritten und der vierten Klassenstufe ergab, dass sich die sprachliche Komplexität der Aufgaben vor allem für jüngere Grundschulkinder unabhängig von ihrer Familiensprache benachteiligend auswirkte. / Large-scale assessment studies have repeatedly documented performance disadvantages of language minority students in German elementary schools. The substantial achievement gap has led to concerns regarding the validity of large-scale assessment items for language minority students. It may be the case that these performance differences are, in part, due to high language demands of the test items. These items may selectively disadvantage language minority students in the testing situation. This dissertation project investigated the connection between the academic language demands of mathematics test items and the test performance of monolingual students and language minority students. First, it was investigated whether the test items were differentially valid for language minority students. Moreover, the connection between the differential validity and the linguistic complexity of the test items was tested. The findings indicated that overall, differential validity of the examined tests for language minority students was low. However, the test items’ language demands were related to differential validity. The largest proportion of item-specific performance disadvantages was explained by confounded combinations of several linguistic features. Additionally, unique effects of descriptive, lexical, and grammatical features were identified. An experimental study showed that linguistic simplification did not seem to be a promising method to substantially reduce the performance differences between language minority students and German monolingual students. A comparison of differential effects of mathematics items’ language demands for language minority students over two adjacent grade levels indicated that the impact of academic language demands seemed to depend on grade level rather than on language minority student status. Regardless of their home language, younger students seemed to struggle more with linguistically complex test items than older students.

[pt] Este estudo compara o Letramento Científico dos estudantes brasileiros e japoneses, com base nos resultados do PISA e procura responder às seguintes as questões de pesquisa: a) Há diferenças de competência cognitiva em Ciências entre os alunos brasileiros e dos outros países, sobretudo os do Japão no PISA?; b) Existem itens do PISA 2006 que apresentam comportamento diferencial, tendo o Brasil como referência?; e c) É possível, a partir dos dados do PISA e da adoção complementar de uma abordagem qualitativa, identificar diferentes ênfases curriculares e/ou práticas pedagógicas no Ensino de Ciências de Brasil e Japão que contribuam para a compreensão das diferenças de desempenho entre seus estudantes? Para responder a primeira questão, comparamos os resultados do Brasil e do Japão nas edições 2006 e 2015 do PISA, em que o foco foi Ciências. O Brasil se mostra em situação de desvantagem em relação a quase todos os países que participaram do Programa, o que é em parte explicado pela repetência. Na escala de desempenho, o Brasil permanece no nível 1 e o Japão, no nível 3 em2006, passou para o nível 4 em 2015. Para responder à segunda questão, utilizamos a análise de Differential Item Functioning (DIF) nos itens da prova de Ciências de 2006 e concluímos que há grande presença de DIF nesses itens comparativamente entre o Brasil e o Japão. Apesar de não serem capazes de comprometer o processo avaliativo privilegiando um grupo em detrimento do outro, esses itens sugerem diferentes ênfases curriculares em Ciências. Levando em conta essa hipótese e para responder à terceira questão adotamos uma abordagem qualitativa, com observação do uso do tempo das aulas; registro das ênfases curriculares e da ocorrência de atividades relacionadas à interação, investigação, experimentação e aplicação na perspectiva dos alunos, professores e da observação; e entrevistas com especialistas e gestores. Os resultados mostraram que mais de 20 por cento do tempo oficial de aula observados no Brasil são desperdiçados com questões outras que não o ensino efetivo de Ciências; 10 vezes mais que no Japão. No Brasil, há ênfase curricular mais acentuada nas Ciências Naturais e Biológicas. O currículo é distribuído mais homogeneamente no Japão e é seccionado no Brasil. Segundo os estudantes japoneses, não são freqüentes as atividades de interação, investigação, experimentação e aplicação. As atividades mais recorrentes observadas e percebidas pelos professores japoneses são as de experimentação e interação; no Brasil, as de interação e aplicação. Entrevistas realizadas com especialistas em Ensino de Ciências e gestoras do PISA, no Brasil e no Japão, mostraram que o sucesso do Japão nessa avaliação é associado à existência de um currículo nacional comum e à formação continuada de professores em serviço, bem como às reformas do sistema educacional japonês suscitadas pelos resultados do PISA. O baixo desempenho dos estudantes brasileiros no PISA estaria, por sua vez, relacionado com o despreparo dos estudantes, com a falta de familiaridade destes com o teste, com a deficiente formação dos professores e com o limitado uso das evidências produzidas pelas avaliações em larga escala. / [en] This study compares the Scientific Literacy of Brazilian and Japanese students, based on the results of PISA and seeks to answer the following research questions: a) Are there differences of cognitive competence in Science among Brazilian students and those from other countries, especially Japan, in the PISA ?; B) Are there items of PISA 2006 that present differential functioning, with Brazil as a reference ?; and c) Is it possible, based on the PISA data and the complementary adoption of a qualitative approach, to identify different curricular emphases and / or pedagogical practices in Science Education in Brazil and Japan that contribute to the understanding of differences in performance among their students? To answer the first question, we compared the results of Brazil and Japan in the 2006 and 2015 editions of PISA, where the focus was Science. Brazil is disadvantaged compared to almost all the countries that participated in the Program, which is partly explained by the repetition. In the performance scale, Brazil remains at level 1 and Japan at level 3 in 2006 has moved to level 4 in 2015. In order to answer the second question, we used the Differential Item Functioning (DIF) analysis in the 2006 test s Science items and we conclude that there is a large presence of DIF in these items comparatively between Brazil and Japan. Although they are not able to compromise the evaluation process by favoring one group over the other, these items suggest different curricular emphases in Science. Taking into account this hypothesis and to answer the third question we adopted a qualitative approach, with observation of the use of class time; record of curricular emphases and the occurrence of activities related to interaction, investigation, experimentation and application from the perspective of students, teachers and observation; and interviews with experts and PISA managers. The results showed that more than 20 percent of official classroom time observed in Brazil is wasted with questions other than effective teaching of science; 10 times more than in Japan. In Brazil, there is a more pronounced curricular emphasis in Natural and Biological Sciences. The curriculum is distributed more homogeneously in Japan and is sectioned in Brazil. According to Japanese students, activities of interaction, investigation, experimentation and application are not frequent. The most recurrent activities observed and perceived by Japanese teachers are those of experimentation and interaction; In Brazil, those of interaction and application. Interviews with experts in Science Education and PISA managers in Brazil and Japan have shown that Japan s success in this assessment is associated with the existence of a common national curriculum and the teachers ongoing in-service training as well as the educational system reforms raised by the PISA results. The low performance of Brazilian students in PISA would, in turn, be related to the lack of preparation of the students, their lack of familiarity with the test, poor teacher training and the limited use of the evidence produced by the large scale evaluations.

MAIA, José Leudo. Uso da Teoria Clássica dos Testes – TCT e da Teoria de Resposta ao Item – TRI na avaliação da qualidade métrica de testes de seleção. 2009. 325f. Tese (Doutorado em Educação) – Universidade Federal do Ceará, Faculdade de Educação, Programa de Pós-Graduação em Educação Brasileira, Fortaleza-CE, 2009. / Submitted by Maria Josineide Góis (josineide@ufc.br) on 2012-07-10T11:42:58Z No. of bitstreams: 1 2009_Tese_JLMaia.pdf: 4582126 bytes, checksum: 35b2f8279baa21b052a910889b5a7001 (MD5) / Approved for entry into archive by Maria Josineide Góis(josineide@ufc.br) on 2012-07-13T11:49:37Z (GMT) No. of bitstreams: 1 2009_Tese_JLMaia.pdf: 4582126 bytes, checksum: 35b2f8279baa21b052a910889b5a7001 (MD5) / Made available in DSpace on 2012-07-13T11:49:37Z (GMT). No. of bitstreams: 1 2009_Tese_JLMaia.pdf: 4582126 bytes, checksum: 35b2f8279baa21b052a910889b5a7001 (MD5) Previous issue date: 2009 / sse trabalho doutoral tem como proposta fazer uso da Teoria Clássica dos Testes – TCT e da Teoria de Resposta ao Item – TRI como instrumentos na avaliação da qualidade métrica de testes de seleção, sob quatro aspectos de investigação: Análise da Validez do Construto; Análise Psicométrica dos Itens; Funcionamento Diferencial dos Itens – DIF; e Função de Informação. Para tanto, foram utilizados dados dos resultados das provas de Português e Matemática do concurso vestibular da Universidade Estadual do Estado do Ceará – UECE, de 2007, em que participaram 20.016 candidatos a 38 Cursos de Graduação, somente na Capital do Estado. Para o tratamento desses dados, foram utilizados os seguintes softwares: SPSS, v15; BILOG-MG, v3.0; MULTILOG FOR WINDOWS, v1.0; e o TESTFACT v4.0. A primeira providência foi verificar a dimensionaidade dessas provas. Para tanto se utilizou o Método de Kaiser-Guttman, Scree-plot, e o Método das Cargas Fatoriais e das Comunalidades da Matriz de Fatores. A constatação foi de que a prova de Português apresentava características multidimensionais, sendo, portanto, descartada, por não atender aos pressupostos básicos da Unidimensionalidade e Independência Local dos Itens. A prova de Matemática, no entanto, por apresentar comportamento unidimensional, se tornou o foco deste trabalho. A análise da Validez do Construto foi realizada por meio dos coeficientes Alpha de Cronbach e Kuder-Richardson, tendo gerado valores iguais a 0,685, além da utilização, também, do método das Cargas Fatoriais, com cargas entre 0,837 e 0,960, indicando intensa consistência interna. A análise psicométrica dos itens foi realizada por meio dos índices de dificuldade, discriminação e acerto ao acaso, para ambas as teorias, indicando ser essa uma prova de dificuldade mediana, com bom comportamento discriminativo e baixo índice de acerto ao acaso. A análise do DIF foi realizada, segundo o gênero dos candidatos, pelos métodos Delta-plot, Maentel-Haenszel, Regressão Logística e Comparação dos Betas, indicando resultados estatísticamente não significativos, no que se concluiu não apresentar, a prova, comportamento diferenciado, segundo o gênero. A análise da Função de Informação da prova permitiu se observar que esta é particularmente válida para candidatos com aptidão em torno de 0,8750 e que, a um nível de confiança de 95%, 49,3% dos candidatos atenderiam a essa indicação. Observou-se também que 90,6% dos candidatos, em ambos os processos, apresentaram o mesmo nível de aptidão, indicando uma convergência bastante razoável entre os resultados gerados pela TCT e TRI, no entanto, no estudo amostral, a TRI identificou que 9,4% dos candidatos apresentaram maior aptidão para a realização de um curso superior que os selecionados pela TCT.