Purpose: Designed to measure, together with the WJ III Ach, intellectual abilities and academic achievement.
Population: Ages 2 to 90+
Scales: Verbal Ability, Thinking Ability, Cognitive Efficiency, Supplemental, Intra-Cognitive Discrepancies, Predicted Acheivement and General Intellectual Ability (GIA)
Time: 60-70 minutes.
Authors: Richard Woodcock, Nancy Mather, Kevin McGrew
Publisher: Riverside Publishing
Description: The Woodcock Johnson III - Tests of Cognitive Skills (WJ III COG) updates and expands the WJ-R Tests of Cognitive Ability (WJ-R COG) and is designed to measure general and specific cognitive functions. The other battery the WJ III ACH is designed to identify and describe an individualís current strengths and weaknesses. When these two batteries are administered together, they allow the tester to investigate over-underachievement and to examine patterns of intra-individual discrepancies among cognitive or achievement areas. The batteries of the WJ III COG and WJ III ACH are further classified as standard or extended. New tests, clusters and interpretive procedures have been added with the intension of improving the diagnostic power of the instrument and increasing the breadth and depth of coverage. The clusters are grouped into three cognitive areas, Verbal Ability, Thinking Ability, and Cognitive Efficiency. Oral language tests have been moved to the WJ III ACH.
Scoring: Requires scoring during testing to determine basal and ceiling levels. Raw scores are totaled and converted into age and grade equivalents, percentile ranks, and discrepancy scores with use of the Scoring Tables. Compuscore and Profiles Program are used for all other scoring. The WJ III COG provides two indices of general cognitive functioning (i.e., intelligence) by means of the General Intellectual Ability (GIA) score and the Brief Intellectual Ability (BIA) score.
Reliability: The median reliability coefficient alphas for all age groups for the standard battery of the WJ III COG for tests 1 through 10 ranged from .81 to .94. For the Extended battery, median coefficients ranged from .74 to .97. The reliability scores for the WJ III meet or exceed standards. The median cluster reliabilities are mostly .90 or higher, and the individual test reliabilities are mostly .80 or higher, and can be used for decision making purposes with support from other sources.
Validity: The technical manual presents a considerable amount of evidence supporting the validity of scores from the test, noting that the earlier versions of the battery have also been shown to have validity. Test content on the WJ III COG has emerged from previous versions, is similar to the content found on other well-established cognitive measures, or is based on sound experimental instruments.
Norms: The normative samples (pre-school, school aged, college and adult) were selected to be representative of the US population, based on geographic distribution, community size and type, and SES, occupational status, sex, race.
Suggested use: The WJ III Tests of Cognitive Ability has uses for educational, clinical or research purposes. As a diagnostic tool, it can determine specific strengths and weaknesses, and can help associate certain factors on future development. Intra-ability, intra-individual and ability/achievement discrepancies can be useful in determining the existence of specific disabilities, and in selection for LD programs. The test results may be helpful ins educational programming, individual program planning, guidance, in assessing growth, in research and evaluation and it is an excellent instrument for introducing individual assessment in college and university courses. psychometric training.