Douglas Fuchs and Lynn S. Fuchs, Peabody College of Vanderbilt University; Patricia G. Mathes, University of Texas--Houston Health Science Center; Mark W. Lipsey and P. Holley Roberts, Peabody College of Vanderbilt University
Learning Disabilities Summit: Building a Foundation for the Future White Papers
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In the 1990s, an "NICHD group" became the most important voice expressing dissatisfaction with current LD definitions and encouraging fundamental change in our thinking about LD. The "NICHD group" refers in part to the principal investigators of learning disabilities centers funded by the National Institute of Child Health and Development (NICHD) and to Reid Lyon, the branch chief who supervises and coordinates their work. Our descriptor for this group is admittedly imprecise because we include researchers without NICHD funding who have conducted similar research, and we have little reason to believe everyone in the group thinks alike on all issues. Nevertheless, the group's work is sufficiently cohesive and important for us to regard it as an entity, and sufficiently tied to NICHD for us to use the acronym as an adjective. This group is different from the REI advocates in many ways. The NICHD group consists mostly of developmental, experimental, clinical, and neuropsychologists; REI advocates were largely special educators. The NICHD group focuses mostly on reading disabilities; REI supporters focused on the broad range of learning disabilities. Perhaps the most important difference between the groups is that the NICHD group claims to recognize the legitimacy of the LD construct. Lyon et al. (2001) have written, "Few would disagree that 5% or more of our school-age population experience difficulties with language and other skills that would be disruptive to academic achievement. The concept of LD is valid" (p. 7). What is invalid, says the NICHD group, are the definitions and operationalizations of the construct, which, they insist, must be reconceptualized.
Many concerns exist about IQ discrepancy as a definition or operationalization of LD, several of which already have been described. In addition, there are statistical problems (e.g., Willson, 1987) and the rejection by many of IQ as a meaningful estimate of overall intellectual potential (e.g., Spear-Swerling & Sternberg, 1998). The NICHD group's principal interest in the IQ discrepancy has been to explore the criterion validity of the "two-group hypothesis"; that is, the belief that qualitative differences exist between (a) children whose poor reading is discrepant from their IQ and (b) children whose poor reading is not discrepant from their IQ. This work has included a review of earlier studies conducted by others, secondary analyses of extant work, and the implementation of primary research.
"Earlier studies," wrote Fletcher (1995), "provided at best equivocal evidence for the validity of the two-group hypothesis. Many studies yielded null results, while other studies observed small but statistically significant differences between the two groups" (p. 16). Fletcher dismissed this earlier research with the claim that it suffers from methodological weaknesses that compromise its findings. In recent years, the NICHD group has conducted at least four studies on IQ discrepancy and the validity of the two-group hypothesis (Fletcher et al., 1994; Foorman, Francis, & Fletcher, 1995; Francis, Shaywitz, Stuebing, Shaywitz, & Fletcher, 1996; Stanovich & Siegel, 1994). Two of these studies (Fletcher et al. and Francis et al.) used extant data from Shaywitz and colleagues' Connecticut Longitudinal Study (Shaywitz, Escobar, Shaywitz, Fletcher, & Makuch, 1992). The four studies are noteworthy for (a) their researcher-defined samples, (b) their broad selection of concurrent child measures, and (c) the systematic way in which the studies build on each other. Each of these studies fails to support the two-group hypothesis. Moreover, authors of these studies have argued that many related investigations have demonstrated that "IQ scores do not predict who is able to benefit from remediation" (Siegel, 1999, p. 312). Or, as Fletcher put it, "There is no evidence that low-IQ and high IQ poor readers respond differently to treatment" (p. 41). Hence, the NICHD group contends that predictive and concurrent validity studies indicate that poor readers characterized by an IQ-achievement discrepancy are no different from poor readers without this discrepancy in terms of most reading-related skills.
Share, McGee, and Silva (1991, cited in Fletcher, 1995) have written, "Professional preoccupation with IQ...is liable to obscure those significant advances achieved over the last 15 years in the field of reading research...to identify domain-specific factors...that are more potent than all-purpose measures, such as IQ. More importantly, these domain specific factors go much further than IQ in helping us understand and deal with reading failure" (p. 43). One important domain-specific factor, according to the NICHD group, is phonological processing. According to Fletcher (1995), Morris et al. (1998), Share et al. (1991), Siegel (1989, 1999), Stanovich (1999), Stanovich, Siegel, and Gottardo (1997), Torgesen, Morgan and Davis (1992), Vellutino et al. (1996), Wagner et al. (1997), and others, phonological processing figures prominently among the information-processing operations that are believed to underlie severe problems in word recognition. The NICHD group claims that phonological deficit should be recognized as a valid LD marker.
Further, they estimate about 25% of the student population demonstrates phonological deficits and argue that all of these children should be understood as reading disabled: "We have chosen to combine the [reading disabled] designation with children who (a) meet criteria for LD and typically receive services through special education; and (b) read below the 25th percentile but who do not qualify for the diagnosis of LD and often receive services through compensatory education [because] data [indicate] little difference between the two groups in the proximal causes of their reading difficulties" (Lyon et al., 2001, pp. 3-4).
Twenty-five percent of 50 million school-going children equals 12.5 million students. Together with approximately 3 million special-needs children who are not LD, this recommendation produces a population of students with disabilities of about 15.5 million, more than 2.5 times the number currently served under the Individuals with Disabilities Education Act (IDEA). With 12.5 million children identified as LD, one might expect strong political pressure to reconceptualize this large group in terms of "nondisabled students in need of more effective general instruction."
The key to more effective instruction, says the NICHD group, is early identification and prevention. In his March 8, 2001, testimony before the U.S. House Subcommittee on Education and the Workforce, Lyon asked, "Can children with reading problems overcome their difficulties?" He answered, "Yes, the majority...can learn to read at average or above levels, but only if they are identified early and provided with systematic, explicit, and intensive instruction in phonemic awareness, phonics, reading fluency, vocabulary, and reading comprehension strategies" (p. 3). Moreover, he informed Congress, "Sufficient data exist to guide the development and implementation of early identification and prevention programs for children at-risk for LD" (p. 2). Early identification and prevention, says the NICHD group, should occur in general education: "Given that the underlying causes of most reading difficulties are similar for children regardless of whether they are currently served in special or compensatory education programs, we argue that the most valid and efficient way to deliver this early intervention in reading is as part of regular education" (Lyon et al., 2001, p. 20). However, a "major problem with such efforts is that special educators who typically provide instruction to children with LD have not been integrated into the early identification and prevention initiatives. It is important that both regular and special education embrace these efforts..." (Lyon et al., 2001, p. 36).
Many of the NICHD group's views about and policy recommendations for children with LD (and, more generally, for special education) are strikingly similar to those advanced by REI adherents in the 1980s. Both groups (a) are critical of special education effectiveness; (b) recommend that special education dollars should be combined with Title I dollars and possibly other funding streams to support the professional development necessary to strengthen general education's capacity to accommodate all low achievers; (c) argue that, with this accomplished, many special-needs children will be in mainstream classrooms, thereby permitting a reduction in the size and cost of special education nationwide; and (d) promote the notion that special educators' roles must change. REI adherents argued that special educators should become consultants and coteachers; the NICHD group recommends that they become heavily involved in early identification and prevention.
Most important, both groups view LA children with and without the LD label as the same children. For the NICHD group, "all low achievers are LD"; for the REI group, "all children with LD are low achievers." Although the NICHD group claims to believe in the validity of the LD construct, its critique of LD definitions and operationalizations seems to raise fundamental questions about the category. For example, Lyon et al. (2001) ask rhetorically, "Is the definition of LD that guides assessment and diagnostic practices too general and ambiguous to ensure accurate identification of younger students? Are the constructs and principles inherent in the definition of LD [invalid]? Are the diagnostic practices biased against the identification of younger, poor, or ethnically different children with LD?" (p. 7). To each question, they answer "yes." Similarly, Fletcher (1995) has written: "We have shown that the two-factor [poor readers with and without the LD label] classification implicit in the Federal Register definition lacks validity" (pp. 45-46). The NICHD group's dismissal of the distinction between low achievers with and without the LD label would seem to encourage a reconceptualization of children with LD--a subsumption of these children into a much larger, nondisabled group (i.e., the 12.5 million poor readers who, according to the NICHD group, require early identification and intensive prevention in general education). Hence, statements of support for the LD construct notwithstanding, the NICHD group, like the REI group before it, appears to be questioning whether the LD category deserves continued support.
Funding for NRCLD is provided by the U.S. Department of Education, Office of Special
Education Programs. Award No. H324U010004. Opinions expressed herein are those of the National
Research Center on Learning Disabilities and do not necessarily represent the position of the U.S.
Department of Education.
© 2007 National Research Center on Learning Disabilities
Last Updated: November 19, 2007
Contact: nrcld@ku.edu