Rasch Analysis of a Rating Scale for Gifted and Talented Identification

Abstract

A paradigm shift toward a talent development model of providing services in gifted education has transformed the traditional IQ-based notion of giftedness (Dai & Chen, 2013). The conceptualization of giftedness plays an important role in the development of programs for gifted and talented students, and at its core the conceptualization of giftedness plays a central role in the development of instruments for identification, including rating scales completed by teachers and other school-based staff (Borland, 2003; Robinson, 2009). This study used Rasch measurement analyses to evaluate the evidence of validity, characteristics of reliability, item selection, category structure and differential item functioning of the Scales for Rating the Behavioral Characteristics of Superior Students, 3rd Edition ([SRBCSS-III] Renzulli et al., 2013) using data from the SRBCSS authors' validation studies and data from Grade 3 and Grade 4 operational administrations in a Mid-Atlantic county school district. The Rasch rating scale model showed evidence for the substantive, structural and content validity aspects of construct validity in both the original validation studies and the operational administrations. Strong item hierarchies, content representativeness and data reliability were shown in the analyses. Additionally, data from the operational administrations showed minimal differential item functioning for groups analyzed by sex, race/ethnicity and economic status. The study highlighted the strength of the psychometric properties of the scales while offering suggestions for improvement and future study in the context of additional aspects of validity.