WESCHLER INDIVIDUAL ACHIEVEMENT TEST

James Becker, Ben Hammond, John Rutledge

What Is The WIAT?

Many contributors; authored by

“The Psychological Corporation”

For grades K-12 or ages 5-19

Norm referenced assessment of achievement levels in 8 curriculum areas

Provides initial assessment of strengths and weaknesses through subtest and composite scores

Provides comparison of intellectual ability (as measured by Weschler scales) and achievement levels in the 7 areas of specific learning disabilities that originally a child could be diagnosed in the Education for All Handicapped Children Act (1975-1990 then IDEA)

ADMINISTRATION AND SCORING CHARACTERISTICS

Individual administration only (no group testing)

Time to take test is 30-50 min for kids & 55 minutes for adolescents

Scores interpreted in terms of standard scores, age equivalencies, grade equivalencies

Standard scores can be directly transformed to stanines, normal curve equivalencies, and percentile ranks

Linked to Wechsler scales, which makes it easy to calculate discrepancy between achievement and ability

WIAT has limitations in its usefulness for assessing students with severe disabilities. The manual states that “if the child has a severe disability that interferes with perception of the test stimuli or completion of item responses, test scores may be invalid, unless effective adaptations of test procedures have been successful” (WIAT manual p.165)

FORMAT CHARACTERISTICS

Test subjects are required to: Listen

Read print

Look at Stimuli

Make one-word and multiple-word responses

Write print, point, and mark answers on a sheet

WIAT

EXAMINER CHARACTERISTICS:

Examiner must have graduate level training in administering standardized assessment to be qualified to administer and interpret scores

NORMS!

Stratified random sample (representative of U.S. population) of 4,252 children in 13 age groups

2,160 females and 2,092 males, evenly distributed in age groups

Race/Ethnicity of sample group based on U.S. population (per 1988 census data... 1988! Red flag!)

Geographic region: divided into four regions Northeast, North Central, South, and West (sampling based on population of students in each region)

Parental education level stratified into five categories

Normative data gathered in 1988 (Red flag: that’s a long time ago!)

RELIABILITY, STABILITY, & VALIDITY

Reliability above 90% for composite scores in all ages and all categories (some

variation by age group)

Stability above 90% for composite scores in all ages and categories except

85% for reading and math composites (some variation by age group)

Validity Test items carefully aligned with curriculum and reviewed in the

context of school textbooks, teacher surveys, expert opinions, and curricular trends related to age and grade

correlates with achievement discriminates on the basis of gender, race, ethnicity and other

demographic variables high degree of correlation with other individually administered

standardized tests (BASIS, K-TEA, WRAT-R, WJ-R, DAS, PPVT-R)

SUBTESTS

Basic Reading Mathematics

Reasoning Spelling Reading

Comprehension Numerical Operations Listening

Comprehension Oral Expression Written Expression

SUBTEST EXAMPLES

Look for these on the left side of intro pages!

Answer page example:

SUBTEST DATA SHEETS

SUBTEST DATA SHEETS CONT.

Handout

QUESTIONS?