The interpretation of retest scores is problematic because they are potentially affected by measurement and predictive bias, which impact construct validity, and because their size differs as a function of various factors. This paper investigates the construct stability of scores on a figural matrices test and models retest effects at the level of…

Infants judged to be at risk for subnormal intellectual growth were randomly assigned to experimental and control groups which varied as to educational curriculum activities. Two types of evidence, group differences and parent-child IQ correlations, demonstrate the importance of early environments in intellectual development. (Author/RD)