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Learning Disability Module


Definition of Learning Disabilities

The definition of LD has evolved over the years as knowledge and research in the field have grown, and legislation has been passed by the federal government to assure the educational rights of students with LD. The following definition taken from the 1968 definition of the National Advisory Committee on Handicapped Children (NACHC) was adopted by the U.S. Office of Education for use in the implementation of the Education of All Handicapped Children Act (PL 94-142, 1975):

Specific learning disability ‘means a disorder in one of more of the basic psychological processes involved in using or understanding language, spoken or written, which may manifest itself in an imperfect ability to listen, think, speak, read, write, spell or to do mathematical calculations. The term includes conditions such as perceptual handicaps, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. The term does not include children who have learning problems which are primarily the result of visual, hearing or motor handicaps, of mental retardation or emotional disturbance, or of environmental, cultural or economic disadvantage. (as cited in Hallahan & Mercer, 2001)

This definition of LD has remained in effect with minor word changes and is reflected in subsequent legislation (i.e., Individuals with Disabilities Education Act of 1990, PL 101-476; Individuals with Disabilities Education Improvement Act of 1997, PL 105-17; Individuals with Disabilities Education Improvement Act of 2004, PL 108-446).

Founded in 1975, the National Joint Committee on Learning Disabilities (NJCLD), a group of 12 professional organizations with interest in children, adolescents, and adults with learning disabilities, was created with the purpose of developing greater cooperation and understanding among its members (LD Online, n.d.). This Committee has made several observations regarding the NACHC definition of LD that are informative:

  • LD is a heterogeneous group of disorders. “These disorders are realized as significant difficulties in the acquisition and use of one or more of the following functions: listening, speaking, reading, writing, reasoning, and math abilities” (American Speech-Language-Hearing Association, 1991, p. 2).
  • LD is generally recognized as a central nervous system dysfunction, but this does not mean that LD diagnosis can only be conducted by a medical professional. Diagnosis of LD requires assessment of psychological, educational and/or language abilities.
  • LD can be accompanied by problems in self-regulation, social perception, and social interaction.
  • LD cannot occur primarily due to cultural, educational, or environmental circumstances (exclusionary clause), BUT LD can occur concomitantly with other disabilities.

The NJCLD developed the following definition of LD, which was proposed in 1981 and revised in 1990. This definition can be applied to adults and is the most commonly used definition of LD today outside of the K-12 system:

Learning disabilities is a generic term that refers to a heterogeneous group of disorders manifested by significant difficulties in the acquisition or use of listening, speaking, reading, writing, reasoning or mathematical abilities. These disorders are intrinsic to the individual and presumed to be due to central nervous system dysfunction. Even though a learning disability may occur concomitantly with other handicapping conditions (e.g., sensory impairment, mental retardation, social or emotional disturbance), or environmental influences (e.g., cultural differences, insufficient/inappropriate instruction, psychological factors), it is not the direct result of those conditions or influences (American Speech-Language-Hearing Association, 1991, p. 4).



American Speech-Language-Hearing Association. (1991). Learning disabilities: Issues on definition. Retrieved from: http://www.asha.org/docs/html/RP1991-00209.html

Hallahan, D. P., & Mercer, C. D. (2001). Learning disabilities: Historical perspectives. Retrieved from http://www.nrcld.org/resources/ldsummit/hallahan.html

LDOnline. (n.d.). National Joint Committee on Learning Disabilities: Member organizations. Retrieved from http://www.ldonline.org/about/partners/njcld#member


Permission is granted to copy this document for educational purposes; however, please acknowledge your source using the following citation:

UDI Online Project. (2011). Learning Disabilities (LD) Module. Center on Postsecondary Education and Disability, University of Connecticut, Storrs. http://udi.uconn.edu/index.php?q=content/learning-disability-module.