Multifactorial models of dyslexia have expanded how we consider heterogeneity within the population of children with dyslexia. These models are predicated on the idea that cognitive/linguistic risk factors are not deterministic but instead probabilistic, with the likelihood of difficulties involving an interaction between risk and protective…

This reprint of an 1866 essay by the physician who identified Down's syndrome describes the physical and behavioral patterns that characterize individuals with mental retardation who come from different ethnic groups. This evidence of degeneration crossing racial divisions is seen as support for the idea that the human family has a common origin.…

The article points out the risk of erroneous classification and inequitable treatment for students who are difficult to teach and manage. Analysis of child count data highlights variability in identification and referral processes and suggests that attempts to tighten eligibility standards, especially for mildly handicapped students, is…

Discusses problems in the process used by the American Association on Mental Retardation (AAMR) to redefine mental retardation and substantive problems with various definitions of mental retardation, including the former and new 1992 AAMR definition. Recommended elements in a new educational definition of mental retardation are presented. (CR)

Discusses what children with developmental language disorders should be called, how they should be defined, and how we might differentiate children with specific language impairments from other children with developmental language disorders. The lack of congruence between clinical and research constructs is discussed. (Author/CR)

It is argued the proposed definition of dyslexia is restricted to developmental dyslexia in which a student struggles to learn to read and does not apply to acquired dyslexia in which a previously normal reader loses reading functions. The need for classification schemes for defining specific learning disabilities is emphasized. (Contains…

Characteristics of the aggressive, severely behavior disordered (BD) child are discussed, with a focus on classification and identification criteria. Additional factors directly related to the behavior of an aggressive, severely BD child are also considered: biological factors, familial factors, cognitive factors, frustration (specifically…

This article addresses the continuity from early speech-language delays to later learning problems in school and recommends use of "language organization disorder" to describe the delay. Chronologies of the difficulties and methods for early detection are provided. A table summarizes 11 research studies on early language delays and later reading…

Research in the field of developmental disabilities has found direct links between severity of a personality trait or psychopathology and particular pathology of the deoxyribonucleic acid (DNA). From studies of behavior phenotypes, new psychiatric disorders are being recognized, such as Williams syndrome. The formulation of valid behavior…

This reprint of one chapter from the 1975 text, "Issues in the Classification of Children" by Nicholas Hobbs and others, addresses the theoretical, methodological, and empirical issues involved in the "labeling" approach to the sociology of deviance. It examines the social process of classification, the use of classification in social agencies,…

This commentary on a previous article that described the use of topological thinking in the field of mental retardation discusses appropriate scientific uses of typologies, what categories are and how they are used in social and biomedical sciences, and the importance of typologies for scientific and practical progress. (Contains extensive…

This rejoinder to a criticism of an article that decried the use of topological thinking in the mental retardation field argues that topological thinking is a form of psychological existentialism that offers a reductive approach to human development. It urges the inclusion of individual as well as group scores in studies. (Contains references.)…

Discusses the revised definition of mental retardation in a 1992 manual by the American Association on Mental Retardation. The key principles that provided the foundation for the development of the new definition are described, including the paradigm shift from facility-based to services-based to supports-based models. (CR)

Argues that an educational definition of mental retardation has to be sensitive to the motivational self-system and the self-regulatory processes that underpin performance of students with mental retardation. The theory of motivational orientation that explains the differences in students with intrinsic motivation or extrinsic motivation is…

A review of the history and current status of screening and differential diagnosis in the field of learning disabilities concludes that continued efforts at refinements in diagnosis/classification are unproductive. The authors offer a variety of concrete recommendations from a data-based perspective to make appropriate educational experiences…