The present study employed data simulation techniques to investigate the 1-year stability of alternative classification schemes for identifying children with reading disabilities. Classification schemes investigated include low performance, unexpected low performance, dual-discrepancy, and a rudimentary form of constellation model of reading…

Determining word meanings that ought to be taught or introduced is important for educators. A sequence for vocabulary growth can be inferred from many sources, including testing children's knowledge of word meanings at various ages, predicting from print frequency, or adult-recalled Age of Acquisition. A new approach, Word Maturity, is based on…

Rasch used a Poisson model to analyze errors and speed in reading tests. An important property of the Poisson distribution is that the mean and variance are equal. However, in social science research, it is very common for the variance to be greater than the mean (i.e., the data are overdispersed). This study embeds the Rasch model within an…