MITRA GHADIMI NOURAN; Jalil Younesi
Abstract
Context: One of ways to prevent mental and behavioral problems, improving psychological capital is composed of four structures hope, optimism, resilience and self-efficacy. Aim: This study aims to construct and validate the scale of psychological capital for public Areas use and its relation to psychological ...
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Context: One of ways to prevent mental and behavioral problems, improving psychological capital is composed of four structures hope, optimism, resilience and self-efficacy. Aim: This study aims to construct and validate the scale of psychological capital for public Areas use and its relation to psychological well-being. Method: The research method is correlation, with the statistical population composed of all married people in Tehran, out of whom 520 individuals were selected using the multistep method. The employed scales include the researcher-developed 66-item scale, Luthans 24-item Scale of Psychological Capital (2007), and Ryff psychological Well-being 18-Item Short Form (1995). For the purpose of data analyses, IRT and first- and second-order confirmatory factor analysis were adopted. In order to carry out IRT, the hypotheses of one-dimensionality and local independence were tested and measured by means of VSS, MAP and exploratory factor analysis. Then, five factors namely hopefulness, self efficacy, positive optimism, negative optimism, and resiliency were extracted by means of the first-order confirmatory factor analysis and model fit. In order to investigate whether these five factors were derived from a larger factor, i.e. psychological capital, or not, the second-order factor analysis was used. In order to measure the reliability, internal consistency was adopted as Cronbach's alpha and theta ordinal. Results: As a result of such analyses, the researcher-developed 66-item questionnaire was changed to the 44-item scale. the scale had highly and acceptably reliability coefficient (Cronbach's alpha = 0.945 and theta = 0.952) and Measuring convergent validity، the foregoing questionnaire is in positive، significant relation to Luthans Scale and Furthermore, a positive, significant relation was found between psychological well-being scale and its corresponding six factors. Conclusion: The results suggest that the researcher-developed scale is adequately reliable and valid for the purpose of measuring this construct in various social areas and fields.
Asghar Minaei; Zahra Ghafari
Abstract
The biggest worry, discussed in tests being inequitable, is the presence of bias possibility or differential functioning. Because bias causes test validity to be suspected and doubted. Objective: In this research differential item functioning on the whole 14 blocks of mathematics tests of TIMSS in grade ...
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The biggest worry, discussed in tests being inequitable, is the presence of bias possibility or differential functioning. Because bias causes test validity to be suspected and doubted. Objective: In this research differential item functioning on the whole 14 blocks of mathematics tests of TIMSS in grade 8 between Iranian girls and boys has been studied using IRT approach. Method: In the order that, first, data have been recoded by SPSS and the assumption of items being unidimensional in all blocks, by NOHARM software have been studied. In the next step the best model that is known as “base model” has been fit for data by BILOG-MG software. In the next process from that base model for studying the items having differential functioning and anchor, IRTLRDIF (Thissen,2001) has been used and at last for final estimation of item and ability parameters, MULTILOG software has been used. Findings show that from 219 items, being studied, of mathematics test in grade 8 of TIMSS 2011, 144 anchor items and 75 items have DIF and items have differential functioning and it is to the loss of girls, the focal group.
jalil younesi; ali delavar; mohammad reza falsafi nejhad
Volume 1, Issue 2 , January 2011, , Pages 139-169
Abstract
This study aims to investigate the psychometric characteristics of specialized items of distance education psychology examinations held by Payame Noor University in 2006. To do this, 2000-subject sample was randomly selected from among all those sitting for the distance education psychology exam. Then, ...
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This study aims to investigate the psychometric characteristics of specialized items of distance education psychology examinations held by Payame Noor University in 2006. To do this, 2000-subject sample was randomly selected from among all those sitting for the distance education psychology exam. Then, the sample group was randomly divided into two 1000-subject groups; one of which was used for parameter estimation, and the other for testing model-data fit. In order to analyze the test and its items based on the classical test theory (CTT), in addition to calculating frequency distribution of distracters, items variance, difficulty index, discrimination index and reliability coefficient of the test were computed. In order to analyze the test and its items based on the item- response theory (IRT), assumptions of unidimensionality and local independence were first examined. In this piece of research, in order to determine unidimensionality, all specialized psychology exams were studied in terms of factor analysis by TESTFACT Program. Results of the analyses of the above exams suggested that all of them are unidimensional, and therefore local independence assumptions are verified. Model-data fit was explored by means of BILOG-MG software, and finally, items' parameters (difficulty, discrimination and guessing) estimated along with subjects' ability parameters were extracted. Distracters' analysis showed that all items' distracters were not homogeneous in terms of probability and have had poor performance. It also indicated that in psychology and sociology exams, two-parameter model, and in philosophy exam, three- parameter model were best fit for test items. At the same time, despite the fact that mean of all exams was lower than the criterion score, it seems that the difficulties in the subject of philosophy have been more and this exam had more impact on the subjects' academic failure.
