Journal Issue: Special Education for Students with Disabilities Volume 6 Number 1 Spring 1996
Interventions for Learning Disabilities
Space does not permit an extended review of research on intervention methods for different types of learning disabilities. However, high-quality prospective longitudinal research methods are now being applied to the study of treatment methods for reading disabilities, and that research is summarized here.
Research attempting to identify effective treatment methods for different types and severity levels of reading deficits has been enormously difficult. This is because typical treatment studies have not been able to reliably determine whether the outcomes seen were attributable to the treatment method, the child's general development, the child's previous instruction, the concurrent instruction being provided in the regular classroom, or combinations of these factors. In addition, a majority of treatment studies have been hampered by not having control over teacher expertise and training. Thus, if a treatment method does or does not work effectively, one does not know if it is because of the characteristics of the method, the characteristics of the teacher, or the characteristics of the child.
Since the late 1980s, a number of well-designed longitudinal treatment studies have been conducted. Because these studies have the capability to intervene with children early on and follow them over time, many of the methodological problems described above have been addressed. These intervention studies have provided information about how to prevent reading disabilities as well as how to address reading disabilities once they are detected at later ages.
For example, Blachman and her colleagues59 -61 have shown that instruction in phonological awareness at the kindergarten level has significant positive effects on reading development during the first grade. Within this context, research has demonstrated that proper instruction carried out by informed teachers can prevent reading failure both for children with inherent LD in basic reading skills and for children whose lack of exposure to "language rich" environments and language development activities during the first five years of life places them at risk for reading deficits. For instance, in a series of studies, Blachman60,61 provided 84 low-income, inner-city children with 11 weeks of intensive instruction, 20 minutes per day, with one teacher instructing a small group of four to five students in several aspects of phonological awareness. Prior to instruction, classroom teachers also received 14 hours of intensive training. At the end of the 11 weeks, children receiving the interventions significantly (p < 0.0001) outperformed control children at reading phonetically regular words and at related tasks. A follow-up study conducted in February and May of the first-grade year showed that the gains were maintained if the first-grade curriculum continued the same emphasis on phonological skill development. Similar studies of kindergarten and first-grade children conducted by other researchers62-64 have yielded similar results.
Unfortunately, not all children with reading disabilities have the benefit of appropriate early interventions. As discussed earlier, most children whose reading disability is not recognized until third grade or later and who receive standard interventions fail to show noticeable improvement. However, intensive instruction of appropriate duration provided by trained teachers can remediate the deficient reading skills of many children. For example, in one study, Alexander and her colleagues65 provided 65 severely dyslexic children with 65 hours of individual instruction in addition to group instruction in phonemic awareness and synthetic and analytic skills. This intensive treatment approach improved the reading skills of the children from an initial reading score of 77 to an average of 98.4 (mean = 100) on a measure of alphabetic reading skills. Longitudinal studies continue to demonstrate the efficacy of intensive and informed multidimensional treatment programs.
Several additional findings have emerged from these longitudinal treatment studies. It is clear that children with severe phonological deficits, leading to poor decoding and word recognition skills, respond to treatment at slower rates than youngsters with mild to moderate deficits.44,67 In addition, instruction and interventions for reading failure, which focus primarily on context and reading comprehension without commensurate attention paid to phonological awareness, decoding, and word recognition, show limited results.67-69 Finally, the success of even the best-designed reading intervention program is highly dependent upon the training and skills of the teacher.22,29-31,38
Disability in basic reading skills has been a prime candidate for treatment studies because it is the most common form of LD, it is the most objectively identifiable, and more knowledge is available concerning its causes and developmental course. Interventions for other types of learning disabilities have been developed but not studied as extensively and not studied in prospective, longitudinal research. There is as yet no solid indication whether early, effective interventions for disability in basic reading skills will affect the developmental course of other forms of learning disability.