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Discrepancy analysis

Article ID: 3790
Last updated: 19 Apr, 2010

Federal regulations specify several criteria for determining the existence of a specific learning disability, including underachievement in one or more areas, failure to make sufficient progress in response to targeted intervention, and a pattern of strengths and weaknesses in performance, achievement, or both. (34 CFR §300.309(a)). IDEA 2004 introduces greater flexibility in the assessment process for identifying learning disabilities and/or determining eligibility for special services.

Similar to the WIAT–II, the WIAT–III provides the capability of conducting an ability–achievement discrepancy (AAD) analysis using either the simple difference or predicted achievement method. The WIAT–III also includes the capability of conducting a pattern of strengths and weaknesses (PSW) discrepancy analysis, which most closely resembles the Concordance Discordance Model of SLD identification presented by Hale and Fiorello (2004).

To conduct an ability-achievement discrepancy analysis, you must have the Scoring Assistant installed for both the WIAT-III and a compatible ability test. However, you can conduct a Pattern of Strengths and Weaknesses (PSW) discrepancy analysis with the WIAT-III alone or by creating a combination report with a compatible ability test. Using the WIAT–III Scoring Assistant only, a PSW analysis can be calculating by manually entering scores from the WPPSI–III, WISC–IV, WAIS–IV, DAS–II, or the KABC–II. Unlike the AAD analyses, the PSW analysis can only be calculated using the Scoring Assistant. To reduce the possibility of calculation errors and to ensure results that are accurate and time efficient, tables for manual calculation are not provided in the
Technical Manual CD.

Each of these models may be used within established cognitive and neuropsychological approaches to assessment (e.g., cognitive hypothesis-testing model, the cross-battery assessment approach, Cattell-Horn-Carroll theory, Lurian model).

For a more in-depth discussion of how to conduct a PSW analysis, refer to the Examiner’s Manual Chapter 4.


Article ID: 3790
Last updated: 19 Apr, 2010
Views: 20048
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