1. Stanford-Binet IV Description: –Point-scale (contrast with age-scale of previous editions) –Test composite (M=100, SD=16) –4 areas & scores (M=100, SD=16) –15 subtests (M=50, SD=8)

2. Stanford-Binet IV Psychometrics Standardization sample –5013 subjects –overrepresentation of upper social class & college- educated parents Weighted norms Reliability –Subtests:.80s to.90s range –Internal consistency of Composite:.95 to.99

3. SB IV Psychometrics (cont.) Validity –Criterion-related validity: median of.70; ranges from.21 to.90 depending on range of abilities in specific sample and criterion instrument used –Construct: Factor analysis Support for general ability factor (g) Verbal ability consistently supported Other factors not consistently supported at all age levels

4. SB IV Administration Adaptive testing: testing tailored to individual test taker Use of Vocabulary as “Routing” test Basal & Ceiling

5. Evaluation Reliable & valid measure of overall intelligence Strengths: –Large standardization sample –Efforts to eliminate bias Weaknesses –Overrepresentation of upper class in norms –Not supported by factor analysis at all ages

6. Wechsler Scales Through the Years Wechsler- Bellevue (1939) WISC (1949)WPPSI (1967) WAIS (1955)WISC-R (1974)WPPSI-R (1989) WAIS-R (1981)WISC III (1991) WAIS III (1997)

7. Wechsler Scales 3 versions: WAIS III(16-89); WISC III(6-16); WPPSI (3-7) Commonalities: –Verbal & Performance Scales + Full Scale (M=100, SD=15) WAIS & WISC also divided into “indices” –V & P scales each made up of subscales (M=10, SD=3) Most frequently administered IQ tests; “Gold standard”?

8. WAIS III Standardization sample: 2450 adults 16-89 divided into 13 age bands –1995 census data: age, sex, race/ethnicity, educational level, geographic region How many factors do the Wechsler scales measure? –V & P plus four indices –Are they valid?

9. WAIS III Indices Verbal Comprehension Working Memory Perceptual Organization Processing Speed Vocabulary, Similarities, Information Arithmetic, Digit Span, Letter- Number Sequencing Picture Completion, Block Design, Matrix Reasoning Digit Symbol, Symbol Search

10. WISC III Standardization sample: 2200 kids 6-16 –1988 census race/ethnicity, region of country, parental ed. Level Additional testing of African-American & Hispanic kids to limit bias Several validity studies

11. WPPSI-R Standardization sample: 1700 children in 8 age groups (1/2 year intervals) between 3 years and 7 years & one age group 7-0 through 7-3 –Based on 1986 census estimates Generally considered to be reliable and valid –V & FS from preschoolers predictors of 1st grade achievement, PIQ did not predict achievement