Construct validity of the universal nonverbal intelligence test and the universal brief adaptive behavior index

The purpose of the study was to determine the psychometric and conceptual soundness of new model-based measures of intellectual and adaptive functioning; The Universal Nonverbal Intelligence Test (UNIT; Bracken & McCallum, 1992) and the Universal Brief Adaptive Behavior Index (UBABI; McCallum, 1992). The study was designed to provide evidence for the reliability and construct validity of the scales. Both have been designed to assess constructs of intelligence and adaptive behavior for at-risk children who are limited English language proficient. Multiple sources of empirical test validation were incorporated into this investigation of the UNIT and the UBABI. Participants were 104 elementary, middle, and high school students randomly selected from a rural school district. The UNIT and subtests from the Woodcock-Johnson-Revised Tests of Cognitive Ability (WJ-R; Woodcock & Johnson,1989, 1990) were administered in counterbalanced order using standardized procedures. The UBABI was completed by a classroom teacher of the participant. The UNIT is a multidimensional nonverbal measure developed to assess general intelligence and memory and reasoning constructs. Spearman-Brown correlation coefficients provided evidence of the UNIT’s reliability. Exploratory and confirmatory factor analyses of the UNIT provided evidence for a two-factor structure. Exploratory factor analyses of the UNIT with the WJ-R, yielded support for the UNIT'S measurement of memory and reasoning constructs. Additional evidence of the UNIT'S construct validity was found in correlations among UNIT global scores with age and with composite scores of the WJ-R. The UBABl is unique in its consideration of alternative language systems in the evaluation of adaptive behavior. Cronbach's Alpha and item-subscale correlations were demonstrative of the UBABl's psychometric soundness. Exploratory factor analyses yielded a three-factor structure, Independent Functioning, Communication, and Socialization as a reasonable fit to the data. Empirical support was obtained for the reliability and construct validity of the two instruments. The UNIT and UBABl represent logical steps in the development of theory-driven, multidimensional assessment designed for use with individuals for whom verbal measures are inappropriate. Implications for practical use of the instruments are found in the provision of an underlying theoretical framework to guide test interpretation and hypothesis formation.