Cluster analysis of the differential ability scales : profiles for learning disabled subtypes
| Autor: | McIntosh, David Eugene |
|---|---|
| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Virtual Press. |
| Popis: | The purpose of this study was to determine if distinct subgroups of learning disabled children could be identified using a single, recently developed, instrument--the Differential Ability Scales (DAS). Ward's method of cluster analysis was used to group 83 school-verified learning disabled children from the standardization sample.These children were classified using the core, diagnostic, and achievement subtests of the DAS. Achievement subtest scores were transformed into T-scores with a mean of 50 and a standard deviation of 10 to provide scores on the same scale as the core and diagnostic subtests. Using similar units allowed all scores to contribute more equally during the clustering (Romesburg, 1984).The following six subgroups were identified: (a) generalized, (b) high functioning, (c) normal, (d) underachievement, (e) borderline, and (f) dyseidetic. Not all subgroups displayed the expected discrepancy between intelligence and achievement associated with the current definitions of LD. One subgroup had what might be described as a "normal" diagnostic profile on the DAS. These results were consistent with those of prior subtyping research (Lyon & Watson, 1981; Lyon et al., 1981) where "normal" subgroups were found. Another subgroup obtained General Conceptual Ability scores within the borderline range. Overall, children in this subgroup displayed consistently low scores on all the DAS subtests and achievement commensurate with general ability. In subsequent discriminant analyses, both achievement and diagnostic subtests were necessary for accuracy in classification.This study provided evidence as to the DAS's ability to differentially diagnose the learning disabled and provided distinct profiles for LD subgroups. Administration of the diagnostic subtests along with the score and achievement subtests can provide the clinician with valuable diagnostic information for LD. Department of Educational Psychology |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|