Identifies subgroups of children with reading disabilities using the regression method--children who were poor in phonological, compared to orthographic, word decoding were identified as phonological-type participants, and children who were poor in orthographic, compared to phonological, decoding were identified as surface-type participants. Replicates previous findings that if categorizations are based on comparisons with younger reading-level-matched controls instead of age-matched controls, the number of surface-type children is significantly reduced. (RS)