|
| |
Differential Ability Scales
(DAS)
Step-by-step
Analysis
Step Five: Narrow Ability Hypotheses
- Identify the narrow abilities assessed and any relevant differences between
them
As seen from the previous discussion, despite the fact that the subtests
within each of the DAS clusters measure the same broad ability, one should not
be surprised to find within-cluster differences. When interpreting clusters
found to have divergent subtests, examiners may generate hypotheses relevant to
the subtests themselves. Knowing that Word Definitions and Similarities are both
measures of Verbal ability on the School-Age DAS and also knowing that the first
measures that ability through the use of Lexical Knowledge while the second
measures it through Language Development provides plausible explanations for
differing scores. Flanagan, McGrew, and Ortiz (2000) and McGrew and Flanagan
(1998) provide descriptions of each broad and narrow ability for the major
cognitive assessment batteries, including the DAS.
|
Table XXX-24
DAS Subtests and Proposed Narrow Abilities |
|
|
|
|
|
Verbal Subtests |
|
Narrow Abilities |
|
Verbal Comprehension |
|
Language Development |
|
Naming Vocabulary |
|
Lexical Knowledge |
|
Word Definitions |
|
Lexical Knowledge |
|
Similarities |
|
Language Development |
|
Nonverbal/Spatial Subtests |
|
|
|
Block Building |
|
Visualization |
|
Picture Similarities |
|
Induction |
|
Copying |
|
Visual Memory |
|
Recall of Designs |
|
Visual Memory |
|
Pattern Construction |
|
Spatial Relations |
|
Nonverbal (Fluid Reasoning) Subtests |
|
|
|
Matrices |
|
Induction |
|
Sequential and Quantitative Reasoning |
|
Quantitative Reasoning |
|
Early Number Concepts |
|
|
|
Early Number Concepts |
|
Math Achievement |
|
Diagnostic Subtests |
|
|
|
Matching Letter-Like Forms |
|
Visualization |
|
Recall of Digits |
|
Memory Span |
|
Recognition of Pictures |
|
Visual memory |
|
Recall of Objects-Immediate |
|
Visual memory |
|
Speed of Information Processing |
|
Mental Computational Speed |
|
Adapted from Appendix A, pp. 445 – 453, The Intelligence Test Desk
Reference (ITDR): Gf-Gc Cross-Battery Assessment (McGrew & Flanagan,
1998).
Shaded subtests are those typically administered in the School-Age
Battery |
Additional data may be necessary to reach a meaningful and trustworthy
interpretation. When a significant and unusual difference between subtests leads
you to interpret narrow abilities rather than the broad ability represented by
the cluster as a whole, you are attempting to interpret relatively unreliable,
individual subtests. You will probably need to use other tests of the same
abilities to more fully understand the student's strengths and weaknesses within
the broad ability. Detailed descriptions of abilities measured by other major
intelligence test batteries (e.g., WISC-III and SB:FE) elsewhere in this web
site and the tables in Flanagan, McGrew, and Ortiz (2000), Flanagan and Ortiz
(2000), and McGrew and Flanagan (1998) allow the examiner to select additional
tests to complete the measurement of unusually scattered narrow abilities within
a broad ability classification.
|