Learning Disabilities

Description of the Condition

Learning disabilities (LD) is a well-established term that refers to a broad class of learning disorders typically manifested as a performance difficulty in one or more academic skill areas traditionally taught and assessed in schools. This performance difficulty generally involves the acquisition, rehearsal, retention, retrieval, and recall of symbolic information. Unlike the term itself, the definition of LD is not well established or straightforward. Like many historically significant educational constructs, LD means different things to different people, especially researchers and stakeholders from different educational and psychological disciplines and theoretical perspectives. The current legal definition of LD is established in the Individuals with Disabilities Education Act (1997):

Substantive debate on the true nature and cause of LD has preoccupied the field since Samuel Kirk first coined the term in 1962. While it is difficult to accurately and fully characterize the content of the more recent debates, LD is best represented broadly by two [Page 1378]competing perspectives: the intraindividual differences model and the response to instruction model. The intraindividual differences model, also known as the IQ discrepancy model, focuses primarily on differences found “within” the student as the basis for LD. This model emphasizes the learning attributes of a student and generally relies on the calculation of a discrepancy between a student's individual IQ and his or her achievement as the basis for identifying a learning disability: The greater the discrepancy between a student's aptitude and his or her current achievement in school, the more severe the learning disability. Students are identified using standardized norm-referenced measures of aptitude and attributes, such as processing speed, that frequently do not link directly to instructional remediation. Discrepancies across different abilities are examined, generally at a single point in time, for identification purposes.

In contrast, the response to instruction model, also known as the problem-solving model, is based on an approach that emphasizes a student's response to instruction or intervention in reaching specific outcomes or instructional goals. In this model, the primary focus is on a student's level and rate of performance in comparison to classmates or local norms on curriculum-based measures. Student performance in a given domain in response to instruction (both general and specialized) is assessed over multiple points in time, and response to instruction over time is said to determine the presence or absence of an LD. The response to instruction model consists of four phases: (a) rate of growth on critical skills in a particular domain for all students is documented, (b) students whose level and rate of improvement in performance are below those of their classroom peers are identified, (c) systematic development and testing of classroom adaptations designed to enhance general education instruction is conducted, and (d) the need for special education services is determined.

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