concludes with a summary and discussion of research needed to design effective instruction and instructional supports for low-literate adolescents and adults with disabilities who need to further develop their reading and writing skills.

The findings presented here are relevant to instructors of colleges or adult basic and secondary education programs. Yet it is important to recognize that learning disabilities also are a condition defined by legal criteria in the United States, criteria to which secondary and postsecondary institutions must adhere in providing services for students with learning disabilities. The college students identified with learning disabilities who have participated in research have met this legal criterion. In addition, access for accommodating individuals with learning disabilities on standardized tests and instructional settings requires documentation that these legal criteria have been met. As a result, the findings reported in this chapter may be most relevant to adults with similar characteristics. More research of the kind described is needed to characterize a broader range of adults.


Learning disabilities is an umbrella term that encompasses several types of developmental disorders evident as difficulties in learning specific academic or language skills, typically reading, mathematics, oral language communication, writing, and motor performance (e.g., coordination; see American Psychiatric Association, 2000, Diagnostic and Statistical Manual of Mental Disorders, 4th ed.). Learning disabilities have been historically difficult to define in part because they are not a unitary or homogeneous disorder and in part because they have been defined through exclusionary rather than inclusionary criteria. The rationale for an exclusionary definition remains relevant today. The diagnosis of learning disabilities is reserved for individuals with unexpected academic underachievement that cannot be attributed to known causes, such as sensory disorders, general intellectual disability, significant emotional or behavioral disorders, poverty, language differences, or inadequate instruction (Fletcher et al., 2007).

It is important to note that consensus on an evidence-based definition of learning disability has not yet been reached. There is much debate on how to improve definitions and legal criterion setting for the diagnosis and remediation of learning disability. Further research is needed to arrive at an evidence-based definition to guide research and practice.1 Our main focus


1Traditional diagnoses of learning disabilities have depended either on (a) showing a significant discrepancy between reading, writing, or math achievement scores and the scores that would be expected based on the individual’s IQ scores (IQ/achievement discrepancy definitions) or (b) substantial underachievement in an academic area in the context of average or

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