The dimensionality of phonological awareness: An application of item response theory

A battery of 7 tasks composed of 105 items thought to measure phonological awareness skills was administered to 945 children in kindergarten through 2 nd grade. Results from confirmatory factor analysis at the task level and m odified parallel analysis at the item level indicated that performance on t hese tasks was well represented by a single latent dimension. A 2-parameter logistic item response (IRT) model was also fit to the performance on the 105 items. Information obtained from the IRT model demonstrated that the ta sks varied in the information they provided about a child's phonological aw areness skills. These results showed that phonological awareness, as measur ed by these tasks, appears to be well represented as a unidimensional const ruct, but the tasks best suited to measure phonological awareness vary acro ss development.