Woodcock Johnson Test of Achievement

Woodcock Johnson Test of Achievement

Outline

General Information

• Woodcock Johnson Test of Achievement 3rd Edition
• Riverside Publishing
• Authors: Richard Woodcock Ph.D., Nancy Mather Ph.D. and Kevin S. McGrew Ph.D.
• Battery of 10-42 subtests, 5-10 min each
• $444.00 for WJ III ACH Battery
• Test measures both cognitive ability and academic achievement

• General Information
• Purpose and Nature of Test
• Practical Evaluation
• Normative data
• Reliability
• Validity
• Reviewer comments
• Summary
• References

Normative Data

Revision History

• Test cannot be scored by hand, score is a product of normative analysis.
• Provides deficiency data for further testing
• Co-normative between WJ III COG and ACH
• Normative data for grades K-Grad
• Normative data for ages 2-90+

Normative Data

• Norms grouped by grade, minimum n = 198 (graduate student) maximum n=582 (4th grade)
• Population size: 5,948
• Further grouped by decade (i.e. 20-29, 30-29, etc.) minimum n=147 (80+) maximum n=1,011 (20-29)
• Population size: 8,818
• Randomized 10 community and 13 socio-economic variables
• Uses continuous-year norms

Reliability

Subtests

Normative Data

• Test-retest reliability for the achievement subtests in the battery vary from 0.69 to 0.96 with an average reliability of 0.83 and a median of 0.88
• Inter-rater reliability scores largely not applicable, average reliability of 0.81 for those which it is.

• Benefit to co-norming two tests: discrepancy scores
• Percentile rank
• SD discrepancy
• Intra-Ability discrepancy
• Intra-Individual
• Intra-Cognitive
• Intra-Achievement
• Ability/Achievement Discrepancy
• Predicted/actual achievement
• Intellectual/achievement
• Oral language ability/achievement

• WJ-R (1989)
• Integrated Gf-Gc Theory
• Larger normative sample
• Item revisions
• WJ III (2001)
• Increased use of Cattell-Horn-Carroll Theory
• Addition of 7 subtests
• 5 broad categories added to WJ III COG
• WJ III COG divided into verbal/thinking ability and cognitive efficiency
• Normative update to WJ III (2007)

Validity

Reliability

• Face validity - W scores correlated to known developmental patterns.
• Construct validity - Confirmatory factor analytic models conforming to the ability strata defined by CHC theory
• Construct validity - Moderate inter-correlation between unrelated clusters (0.5-0.7)

• Alternate forms reliability was determined via 100-400 item banks arranged on a difficulty gradient.
• Forms A and B correlate between 0.85 and 0.96 for various age groups.

Validity

• Concurrent Validity - General and Brief Intellectual ability scores of the WJ III COG correlate with Wechsler at ~0.7
• Concurrent Validity - WJ III ACH correlates at 0.78 with Wechsler Individual achievement test.

Reviewer Comments

• "Substantive Evidence....Broad and narrow abilities are measured" (Shrank, 2001)
• "Good concurrent validity overall" (Shrank, 2001)
• "Reliabilities are sufficiently high, almost all in the .90’s" (Shrank, 2001)

Purpose and Nature of Test

• 20 tests of cognitive ability, 22 tests of achievement
• Verbal/thinking ability, cognitive efficiency
• Reading (5 tests) Oral Language (4 tests) Math (4 tests) Written Language (4 tests) Knowledge (1 test) Supplemental (4* tests)
• Standard Battery (12 tests)
• Extended Battery (22 tests)

• Woodcock-Johnson Psychoeducational Battery 1977
• Authored by Richard Woodcock Ph.D. and Mary Bonner Johnson
• First of it's kind: IQ/Achievement battery
• Became diagnostic criteria of learning disabilities
• Ages 2-90+

Summary

• The WJ III Test of achievment displays superior strengths in measuring the total cognitive profile of an individual
• Co-normative data allows valid inferences to be made within a single test
• Test could do a better job representing ethnic and socio-economic minorities.

References

• Flanagan, D. (2001). Comparative Features of the WJ III Tests of Cognitive Abilities (Woodcock-Johnson III: Assessment Service Bulletin No. 1) Itasca, IL: Riverside Publishing.
• McGrew, K.S., Werder, J.K., & Woodcock, R.W. (1991). WJ-R Technical Manual. Itasca, IL: Riverside Publishing.
• Plake, B., Impara, J., & Spies, R. (2003). Fifteenth Mental Measurements Yearbook. Lincoln, NE: University of Nebraska Press.
• Schrank, F. A., McGrew, K. S., & Woodcock, R. W. (2001). Technical Abstract (Woodcock-Johnson III Assessment Service Bulletin No.2). Itasca, IL: Riverside Publishing.
• Woodcock, RW, McGrew, KS, & Mather N (2001) WJ OOO Otasca, IL: Riverside publishing

Practical Evaluation

• Scoring
• Comparison to normative data for grade
• Standard Score
• Percentile Rank
• W score

• Analyzes 5 Broad CHC Factors:
• Reading-Writing (i.e. reading/writing fluency)
• Mathematics (i.e. calculation)
• Comprehension-knowledge (i.e. Story recall)
• Auditory processing (i.e. sound spelling)
• Long-term retrieval (delayed recall)