Contents: Part I:Theoretical and Conceptual Issues in Subtyping. L.V. Feagans, J.D. McKinney, Subtypes of Learning Disablities: A Review. D.L. Speece, D.H. Cooper, Retreat, Regroup, or Advance? An Agenda for Empirical Classification Research in Learning Disabilities. J.W. Hagen, G. Kamberelis, S. Segal, A Dimensional Approach to Cognition and Academic Performance in Children with Medical Problems or Learning Difficulties. R. Plomin, A Behavioral Genetic Approach to Learning Disabilities and Their Subtypes. Part II:Current Research on Subtyping. R.K. Olson, J.P. Rack, F.A. Conners, J.C. DeFries, D.W. Fulker, Genetic Etiology of Individual Differences in Reading Disablility. M. Pressley, Can Learning-disabled Children Become Good Information Processors? How Can We Find Out? L. Meltzer, Problem-solving Strategies and Academic Performance in Learning-disabled Students: Do Subtypes Exist? S.R. Morrison, L.S. Siegel, Arithmetic Disablility: Theoretical Considerations and Empirical Evidence for This Subtype. H.L. Swanson, A Subgroup Analysis of Learning-disabled and Skilled Readers' Working Memory: In Search of a Model for Reading Comprehension. J.K. Torgesen, Subtypes as Prototypes: Extended Studies of Rationally Defined Extreme Groups.