Learning Disabilities as Operationally Defined by Schools

Donald L. MacMillan, University of California, Riverside, & Gary N. Siperstein, University of Massachusetts, Boston
Learning Disabilities Summit: Building a Foundation for the Future White Papers

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ASSUMED INTRINSIC/NEUROBIOLOGICAL ETIOLOGY OF LD

During the late 1970s increased attention was devoted to refining the definition of LD. Zigmond (1993) noted that an improved understanding of the condition emerged from research, in terms of "the psychological, cognitive, neurological, and neuropsychological characteristics of students with learning disabilities..." (p. 256). An alternative definition resulted after years of discussion by the National Joint Committee on Learning Disabilities (NJCLD; McLoughlin & Netick, 1983)--a definition characterized by Zigmond as reflecting "a growing consensus regarding the intrinsic nature of the disorder" (p. 256). The wording in the definition certainly reflected this perspective: "These disorders are intrinsic to the individual and presumed to be due to central nervous system dysfunction" (McLaughlin & Netick, 1983, p. 22). This preoccupation with intrinsic/neurological factors explains in part why so little is known about the contextual influences on the expression of learning disabilities (Keogh & Speece, 1996). Although LD is "intrinsic to the individual, presumed to be due to central nervous system dysfunction" (Kavanagh & Truss, 1988, p. 1), acceptance of this hypothesis does not negate the powerful role of environmental features in either the amelioration or exacerbation of a learning disability. The bias in the scientific study of LD toward intrinsic explanations of the disorder has led to virtual disregard of the contextual factors that either coexist with or are causal to learning disabilities (Speece, 1993). If the problem resides "within the child," then it logically follows that one would not examine experiential factors, home and neighborhood, or parent educational level, as these would be of interest only if they somehow contributed to central nervous system (CNS) dysfunction.

The combination, however, of one-time assessment and the inability to rule out prior instruction and experiential factors as contributors to a child's deficiencies in academics, particularly reading, leads to serious questions about the presumption of a neurological basis for the problem. The more recent research on reading interventions based on phonological awareness noted previously (see Foorman et al., 1997; Torgesen, this volume; Torgesen et al., 2001) suggests that a substantial proportion of young children presenting at one point in time as deficient in reading skills can be taught using moderately intensive interventions. Interestingly, after exposure to these treatments, small percentages (usually 4-10%) of these disabled readers are "nonresponders" who appear to resist even these intensive instructional efforts. Are these (the nonresponders) the cases of "neurologically based" learning problems, while the rest (over 90%) are simply "instructionally underserved"? We suspect that children coming from the most poverty-stricken circumstances not only enter school behind on readiness skills, but also are most likely to be exposed to primary elementary teachers with the least experience or the least success in promoting reading achievement. As long as the schools identify children as LD on the basis of one-time assessments without truly examining response to "good instruction," the practice of classifying them as "learning disabled" (suggesting in-child problems) and presuming a neurological basis for the deficiencies is an inferential leap that is risky at best.

It is also noteworthy that the program of research on reading disability (e.g., Fletcher, et al., 1998; Shaywitz et al., 1990; Shaywitz et al., 1992; Shaywitz, et al., 1995) fails to identify any processing differences between discrepant low readers and nondiscrepant low readers, calling into question the salience of an IQ-achievement discrepancy as a "marker" for reading disabilities. This topic is addressed in detail elsewhere in this volume (see Fletcher et al., this volume) and we raise it here only to further challenge the neurological basis for LD. If nondiscrepant poor readers and discrepant poor readers do not differ on processing variables, apparently either absolute low achievement is indicative of neurological dysfunction or IQ-achievement discrepancy is not a "marker" of such neurologically based learning difficulties presumed to define LD.

CURRICULAR CONSEQUENCES OF THE HETEROGENEITY OF SI LD POPULATIONS

As long as special education and related services for LD students in our public schools absorb students with IQ scores of 70-85 as well as those with scores below 70 there are serious issues to be addressed in the area of curriculum modification. It is clearly evident that the public schools are not willing to identify children in this IQ range as mentally retarded (MacMillan, Siperstein, & Gresham, 1996). Nevertheless, it is equally evident that this group of children is perceived by teachers as among the most difficult to teach and a group that they are going to refer to, and qualify for, special education services regardless of authoritative definitions and eligibility criteria. Third, they are identifying this group as eligible by "certifying" their eligibility as LD students. As indicated previously, we see this neither as a temporary state of affairs nor as one that will be changing in the foreseeable future. As such, LD is currently operationally defined in the public schools as absolute low achievement, not necessarily discrepant from aptitude and not necessarily excluding cases ostensibly due to mental retardation or circumstances suggesting disadvantage of either a sociolinguistic or instructional nature.

To the extent that treatment is linked to labels we must be concerned--that is, if the treatment provided to all children classified as LD assumes homogeneity among those so labeled, and further assumes similar characteristics and needs, we anticipate inappropriate or, at the very least, untested treatments being applied to a segment of the SI LD students. Take, for example, the intervention treatments evaluated on reading disabled students promoting phonemic awareness. As noted above, one finds a nonresponse rate somewhere between 4 and 10% in samples of reading disabled children studied. However, most of those studies set selection criteria for participating at IQ of 80 or above. As such, we have precious little evidence on the usefulness of these treatments with children scoring below IQ 80, yet we find such children in substantial numbers classified as LD. Which of the SI LD students are likely to profit from training in phonemic awareness? Should acquisition of phonemic awareness be a goal on the IEP for all SI LD students or only for some subset with IQ scores of 80 or above?

Last, and possibly most important, the "treatments" provided to SI LD students have been validated on samples absent the low cognitive students. Consider, for example, that the mean IQ of the urban SI LD students in Gottlieb et al. (1994) was 81.4 while the mean IQ scores reported in MacMillan, Gresham, Lopez, & Bocian (1996) for students referred for prereferral intervention were 87.42 for White, 79.93 for Black, and 78.17 for Hispanic students. Yet, in a meta-analysis published by Swanson, Carson, and Saches-Lee (1996) of intervention studies with LD students conducted between 1967 and 1993, they reported a mean IQ across studies for the treatment groups of 95.79 (with a range of 85-106). If the effectiveness of interventions recommended for "LD students" is based on evaluations implemented with mean IQ scores approximating the national average, and the SI LD population in urban districts contains substantial proportions of students with IQ scores a full standard deviation or more lower, then we really don't know how effective such interventions are with SI LD in urban public schools.

Furthermore, we recognize that two second-grade students reading at a standard score of 75, regardless of their IQs, resemble one another and may be taught identically by their teacher. However, if one of these children has an IQ of 98 and the other 65, would one predict the same developmental trajectory for these two children? In other words, would one expect these two students to be reading at the same level in sixth grade assuming they are exposed to the "same treatment"? Assuming the efficacy of a certain reading program documented for children with "normal" intelligence (say IQ 80 and above), is there an IQ threshold below which a beneficial result cannot be predicted? That research, we believe, has yet to be done but is crucial to answering the above questions.

Consequences of this failure to recognize that low cognitive students are being identified as LD and whether intensive reading instruction is the "appropriate" (as in FAPE) treatment for such cases are captured in the following passage. In an article published in the Los Angeles Times describing the differing perspectives of an experienced teacher and of the district director of special education, who is committed to the primacy of reading, one can see the faith of an administrator that all students labeled LD can profit from reading instruction and the belief of a teacher that a functional curriculum would best serve her LD students:

Royalstine Bowman, a 33-year veteran teacher at San Bernardino High School, favors teaching students life skills with a home-grown curriculum that district officials have dubbed "Bowman's Way."

She has little patience with current research that focuses on daily doses of phonics instruction for special education students.

Her approach is based on three decades of experience, salvaging teaching manuals dating to 1942, and a belief that even the most impaired learners can be taught to become independent.

For her students, ranging from ninth- to 12th graders, Bowman's Way means getting drilled on the importance of a firm handshake, a confident introduction and legible handwriting. It means learning how to tell time and how to make change, how to cook and how to fill out job applications borrowed from local fast-food stands and Cadillac dealerships.

For a few students, it also means patient individual help in learning to memorize their home addresses and to spell their last names.

District officials make it clear that they believe Bowman's Way is outmoded. They plan to replace her curriculum with one that makes expert reading instruction a priority.

"I don't care what kind of situation a student is in, being in special education is no excuse for not learning to read," said Joan Roberts, hired a year ago to upgrade the district's special education program. "I want our students learning to read right up to the last second of their senior year."

Bowman counters that "the experts don't know my students."

"The truth is, not every student goes to college," she said. "And nobody asks applicants for jobs as custodians and stock boys what their reading level is." (Colvin & Helfand, 2000, p. 8)

WHERE ARE WE NOW AND WHERE MIGHT WE GO?

It is evident that the "concept" of LD used by the schools deviates markedly from the original concept of LD articulated in authoritative definitions. We have no doubt that the SI LD population reflects a group of children who do, in fact, need assistance; however, among the children identified as LD by the schools are subsets never considered in previous descriptions of LD that acknowledged the heterogeneity present in the original conception of LD (problems in reading, writing, mathematics, verbal expression, etc.). Today, we find children classified as LD who would more appropriately be classified as MR or ED if diagnostic criteria were applied rigorously. As long as the LD category absorbs children with IQ scores in the 70-85 range, as well as those with scores below 70, we will never clean up the LD category. It is of paramount importance that those advocating for a cleansing of LD acknowledge the special needs of these low cognitive children, encourage research that clarifies whether their needs differ in degree or kind from those of the traditional LD child, and advocate for appropriate services for these children. Why? We are convinced that the children whom research criteria would designate as mildly retarded or borderline retarded are far more difficult to teach than a traditional LD child. They require modifications by general education teachers in virtually every curricular area--not just reading. As such, they will continue to be among the first referred and will fill "the special education slots" available at a school site or in a district.

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