Noor-Ali Farroukhi; laila bahrami
Abstract
Background: Recognizing multiple sources of measurement error and estimates each source separately, distinguishes between relative and absolute decisions, distinguishes between fixed and random facets and also the capability of dealing with different D study designs can be mentioned as the strength points ...
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Background: Recognizing multiple sources of measurement error and estimates each source separately, distinguishes between relative and absolute decisions, distinguishes between fixed and random facets and also the capability of dealing with different D study designs can be mentioned as the strength points of generalizability theory which have no corresponding statuses in classical test theory. Generalizability theory is unknown for our researchers and there are rare researches in this area. Objective: The Purpose of this article was introduction of generalizability theory and presentation the practical applicability of this theory in assessing the reliability of measurements. Results: In addition to comparison between classical test theory and generalizability theory, conceptual framework of generalizability theory was explained easily. Also, in this article the process of design, analysis and interpretation of a measurement study in shape of an example with relevant calculations and equations explained in detail in 15 steps to guide researchers and test developers who aimed to assessing reliability. Conclusion: This article shows that utility of generalizability theory in reliability estimation especially in complicated measurement situations is more than classical test theory. Generalizability theory enables researchers to decrease errors in plan of measurement through optimization proceedings which will increase accuracy in generalization of results.
Mohammadreza Falsafinejad; Noorali Farroukhi; laila bahrami
Abstract
Background: High school final exams are one of the most decisive tools for scientific assessment of students. Given the importance of this examinations, carried out systematic research on the quality and functionality of their questions is necessary to separate volunteers. Aim: The aim of this study ...
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Background: High school final exams are one of the most decisive tools for scientific assessment of students. Given the importance of this examinations, carried out systematic research on the quality and functionality of their questions is necessary to separate volunteers. Aim: The aim of this study is to determine the psychometric properties and capabilities of the final exam questions in the field of experimental biology and Persian literature in the selection of candidates for admission to undergraduate courses. Methodology: The population, all of the questions of the third year high school final exams string in June 2011. For determining the psychometric properties of these questions, performance of 600 students, selected randomly, in aforementioned lessons in the school districts of the city of Khorramabad were used. Findings: Estimated reliability coefficient in biology and Persian literature was determined by Cronbach alpha, (0.97, 0.96). According to CTT, the average coefficient of difficulty and discrimination in Persian literature and biology test were (0.65, 0.57) and (0.50, 0.65) respectively. In analyzing the IRT; two-parameter model fitted to the data revealed more. Also, in IRT models, the average difficulty and discrimination of questions for Persian literature and biology courses were (-0.69, 1.03) and (-0.09, 0.96) respectively. The most informant rate for two tests of Persian literature and biology, belongs to levels of ability which are (-0.7, 0.1) respectively, the agreement between the CTT and IRT in terms of discrimination parameter the two courses, were (%98.36, %93.59) respectively. Conclusion: Due to the important decisions based on high stakes tests, implications of final examinations in the selection of candidates were discussed.
