In this 8-year longitudinal study, we traced the vocabulary growth of Chinese children, explored potential precursors of vocabulary knowledge, and investigated how vocabulary growth predicted future reading skills. Two hundred and sixty-four (264) native Chinese children from Beijing were measured on a variety of reading and language tasks over…

Models of irregular word reading that take into account both child- and word-level predictors have not been evaluated in typically developing children and children with reading difficulty (RD). The purpose of the present study was to model individual differences in irregular word reading ability among 5th grade children (N = 170), oversampled for…

Previous research on sensation seeking (SS) was dominated by a variable-oriented approach indicating that SS level has a linear relation with a host of problem behaviors. Our aim was to provide a person-oriented methodology--a probabilistic clustering--that enables examination of both inter- and intra-individual differences in not only the level,…

Inherent limitations on the feasibility of experimentation have made it difficult for investigators to formulate an adequate understanding of individuality as a psychological phenomenon. Recently, Fiske (1979) and Sontag (1971) have suggested that application of a longitudinal or developmental strategy might be of some use in remedying this…

An optimal unbiased classification rule is proposed based on a longitudinal model for the measurement of change in ability. In general, the rule predicts future level of knowledge by using information about level of knowledge at entrance, its rate of growth, and the amount of within-individual variation. (SLD)

The case is made for basing analysis of longitudinal data on each subject's curve of scores. In this analysis of IQ scores from a longitudinal study, fitted curves yielded significant error reduction, rendering untenable the doctrine of IQ constancy. A visual method of curve classification is also presented. (Author/SJL)