"Scatter" and the construct validity of FSIQ: comment on Fiorello et al. (2007).
Two recent articles in this journal (Fiorello et al., 2007; Hale et al., 2007) contended that the WISC-IV FSIQ should not be interpreted for children with disabilities because, when index scores are diverse, the FSIQ lacks validity and is an insufficient description of a child's abilities. This conclusion rested in large part on the authors' use of a model of intelligence that does not include a general ability factor, making the question of the construct validity of the FSIQ meaningless. The present study used simulation methodology to investigate the effect of index score "scatter" on the construct validity of the FSIQ. It found the FSIQ to be equally valid at all levels of scatter, supporting the interpretability of the FSIQ in populations characterized by variable index-score profiles.
Daniel
Mark H
MH
markdaniel@pearson.com
D002648:Child; D003627:Data Interpretation, Statistical; D019988:Children with Disabilities / Q000523:psychology; D006801:Humans; D007361:Intelligence Tests / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D014888:Wechsler Scales