standardization the Second Edition of Reynolds Intellectual Assessment Scales (RIAS-2), in Iran

The purpose of this Research is to "standardization the Second Edition of Reynolds Intellectual Assessment Scales (RIAS-2), in Iran" The main question of this Research was to determine whether the second version of Reynolds Intelligence Scales has desirable psychometric properties in Iranian normative society. The population of the Research consisted of all persons in the age range of 3 to 90 years, numbering 2 0 0 0 perso ns and fro m t h e mo s t populous provinces of Iran have been selected. In the present study, 200 individuals were selected as the sample by using unequal proportional stratified random sampling from each province. The measuring tool of the present study is the second version of Reynolds Intelligence Scales, which was developed in 2015 by Reynolds and Kamphaus to measure intelligence with two factors of crystallized intelligence and fluid intelligence with four target word tests and different Crystallized intelligence and analogical analogy and the missing portion of fluid intelligence were designed and standardized on 2154 individuals in the age range of 3 to 94 years. It has good validity and reliability. In order to investigate the psychometric properties of the mentioned instrument in Iran, by using statistical analysis of the original version, to calculate the coefficients of validity with emphasis on intrinsic homogeneity (with two Cronbach's alpha and split- halph methods) and stability coefficient as well. Validity has been discussed with emphasis on construct validity (with orthogonal hierarchical factor analysis) and concurrent validity (with the fifth version of Stanford-Binet Intelligence Scales). Finally, the research findings showed that the second version of Reynolds Intelligence Scales using two Cronbach's alpha and split-half tests with Spearman-Brown modification to calculate internal consistency above 0.78 as well as stability coefficient which Above 0.82 indicates good validity and indicates reproducibility of the instrument. Also, by analyzing the orthogonal hierarchical factor, it was determined that "fluid intelligence" and "crystallized intelligence" could be considered as one factor in "normative intelligence" in normative individuals .