Score stability is an important psychometric quality of tests intended to measure relatively enduring characteristics such as intelligence. The purpose of the present study was to examine the long-term stability of WISC-R IQs (Full Scale, Verbal, and Performance) for a sample (N = 382) of male and female subjects from three racial or ethnic groups (Anglo, black, Mexican-American). The three-year stability coefficients for the varied sample of subjects (VIQ = .81, PIQ = .78, FSIQ = .85) compared well with those established with a three-week interval during the standardization of the WISC-R. Specific findings indicated that Anglo subjects' IQs were significantly more stable than those of blacks on all three IQ scales and also more stable than those of Mexican-Americans on the Performance and Full Scales. Sex of the subject had minimal influence on test score stability; only females' Verbal performances resulted in significantly larger stability coefficients than those of males. These and other results are discussed from educational, developmental, and psychometric perspectives.
ASJC Scopus subject areas
- Clinical Psychology