The factor differentiation hypothesis suggests that the factor structure of a set of tests tends to differentiate over time, becoming more complex and articulated. This experimental study provides evidence confirming that hypothesis. (Author/JKS)

Two tests of cognitive development, the Cartoon Conservation Scales, Levels I and II, were designed to measure Piagetian stage-related constructs for children of different age groups. The tests were factor analyzed within age levels and were also analyzed using scalogram and tabular methods to test sequential hypotheses. (Author/CTM)