This paper discusses the findings from a study that investigated the information processing characteristics of 93 children (ages 8-16) who have been diagnosed as having either attention deficit hyperactivity disorder (ADHD) only, ADHD-Predominately Inattentive Type, and combined ADHD and learning disabilities (LD). Thirty-nine average students, who had no identified disabilities, were used to compare the three groups of children with ADHD. Results from a discriminate functions analysis showed that the Learning Efficiency Test-II (LET-II) test pattern performance was 83.9 percent successful in differentiating between the three ADHD groups from the average group. The overall group classification rate was 57.6 percent. Examination of the subtest profile of the three groups with ADHD indicated an unusual recall pattern in that there was either an inverted-V or V profile when comparing the impact of verbal interference on serial free recall memory span. The average group showed a more typical profile of losing incrementally more information with each additional source of verbal interference. Results indicate that there are substantial processing differences among the three groups of learners in terms of their levels of information retention and recall, but that there exist characteristic patterns of retention and recall that are similar across the groups. (Author/CR)