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And Miles to Go...:
State SLD Requirements
and Authoritative Recommendations

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Report Text

• Introduction
• SLD Definitions and Classification Criteria
• Historical Overview
• Questioning the Ability-Achievement Discrepancy
• Recommendations for Change in SLD Definition and Classification Criteria
• State Education Agency SLD Definitions and Criteria
• Methodology
• Results
• Analysis of Discrepancy Determination Methods
• Summary of Trends
• SLD Beliefs
• Further Analyses
• Discussion
• References

Figures and Tables

• Figure 1: Distribution of State SLD Prevalence
• Table 1: Consensus Conclusions: LD Summit Follow-Up (Bradley et al., 2002)
• Table 2: Components of State Definitions and Criteria
• Table 3: Methods used to determine the discrepancy
• Table 4: LD Beliefs

Historical Overview

A brief historical review provides the basis for understanding the inconsistencies between SLD definitions and classification criteria. SLD classification criteria and, to a lesser extent, SLD definitions, have been controversial from the earliest origins of the diagnostic construct as a category of educational disability (Cruickshank, 1972, 1979; Kauffman & Hallahan, 1976). The term SLD was suggested by Kirk (1963) and defined by several individuals and associations over the next 20 years (Hammill, 1990). The definition with the most widespread use was formulated in 1968 by the National Advisory Committee on Handicapped Children (U.S. Department of Education [USDE], 1968). This definition acquired semi-official status in 1977 when it was incorporated with only slight revisions into the Federal EHA regulations and continues in Federal IDEA regulations today (IDEA, 1997, 1999, See 34 C.F.R. 300.7).

Although an SLD definition that emphasized underlying process disorders was established in Federal requirements, research developments in the early to mid-1970s precluded using processing deficits as the basis for classification criteria. A series of scathing articles were published in the early to mid 1970s that severely criticized the use of processing assessment and SLD treatments based on overcoming processing deficits (Hammill & Larsen, 1974, 1978; Mann, 1979; Newcomer, Larsen, & Hammill, 1975; Ysseldyke, 1973). The short version of this complicated dispute was that the processing measures were psychometrically inadequate in terms of norms, reliability, and validity. Moreover, the processes identified by SLD process advocates were difficult to change through remedial activities and, more devastating, changes in process competencies did not clearly translate into improved academic performance in relevant domains such as reading, mathematics, and written expression.

The SLD field did not, however, have a sufficient period to reconceptualize SLD in non process terms because of the immediate necessity of developing classification criteria to satisfy an increasingly skeptical Congress. Congress was concerned in the mid-1970s about the new category of SLD and the possibility that the proportion of children with SLD might increase enormously ("Coming Face to Face," 1978; Federal Register, 1976, 1977). Widely varying estimates of the prevalence and sharply differing views of diagnostic procedures and classification criteria existed in the literature and in testimony to Congress as part of the hearings that led to the EHA. Due to concerns about potentially uncontrolled SLD prevalence, Congress then established a temporary cap at 2% of the population as part of the landmark 1975 EHA statute, pending the development of regulations that would establish specific classification criteria for SLD that would limit prevalence and provide guidance to states (Federal Register, 1976, 1977). If these criteria were not published in final form by January 1, 1978, what amounted to a 2% cap on SLD prevalence would become permanent.

A proposed set of regulations to establish SLD classification criteria emphasizing a discrepancy between academic achievement and intellectual ability was published in the Federal Register, November 29, 1976. The most controversial feature of the proposed regulations was the expectancy formula that would precisely define the nature and magnitude of the discrepancy. No mention of processing factors appeared in the proposed SLD regulations or in the revisions eventually adopted. Sharp debate ensued and nearly 1000 mostly critical letters were submitted to the BEH ("Coming Face to Face," 1978; Danielson & Bauer, 1978; Federal Register, December 29, 1977). The field was virtually united in opposition to the expectancy formula due to technical and conceptual issues; however, relatively little discussion of the intellectual ability-achievement discrepancy criterion per se occurred at this time.

The final SLD classification criteria without the expectancy formula were published just prior to the Congressional deadline (Federal Register, December 29, 1977; 34 C.F.R. 300.540-544). As noted previously, the SLD classification criteria specified a severe discrepancy between ability and achievement in 1 or more of 7 achievement areas along with exclusion of other plausible causes. Absent was a discussion of, or guidance on, how the severe discrepancy would be determined or the magnitude of the discrepancy that would be "severe." As shown later in the results, consistent methods for discrepancy determination do not exist across the states or, in many instances, within states.

The subtle, but crucial change in what SLD meant through the SLD classification criteria (Federal Register, 1977) did not receive a lot of discussion in the literature in the late 1970s. An exception was an editorial in the Journal of Learning Disabilities, pointing out that the nearly unanimous outcry against the expectancy formula resulted in overlooking the conceptual shift in SLD from psychological processes to unexplained underachievement (Senf, 1978). The significant shift to severe discrepancy was an uneasy compromise that solved a political problem in the late 1970s. Little research was done on the possible consequences of the severe discrepancy and what was done indicated potentially significant problems with alternative determination methods, reliability, validity, and control of prevalence (Danielson & Bauer, 1978).

A consensus on the best method to determine the discrepancy and the criteria for what constituted "severe" has never been achieved. Some methods are clearly inadequate (Reynolds, 1984, 1985), but debate continues on whether regression-based or simple standard score differences are the most appropriate approaches (Van den Broeck, 2002a, 2002b; Willson & Reynolds, 2002). No research exists to our knowledge that compares the validity of different criteria for what constitutes "severe" in identifying SLD.

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