Psychological Reports, 1991, 69, 23-26. O Psychological Reports 1991
RELATIONSHIPS BETWEEN SCORES O N WECHSLER PRESCHOOL A N D PRIMARY SCALE OF INTELLIGENCE-REVISED A N D STANFORD-BINET I V ' HOWARD H . CARVAJAL, JAMES E PARKS, KIMBERLY J. BAYS, ROBERTA. LOGAN, CAROL I. LUJANO, GREGORY L. PAGE, AND KENNETH A. WEAVER Emporia State University Summary.-The Wechsler Preschool and Primary Scale of Intelligence-Revised and the Stanford Binet-Intelligence Scale: Fourth Edition were given to 5 1 preschool, kindergarten, first, and second p a d e students. Twelve of 15 Pearson correlations between Wechsler IQs and composite and area scores of the Stanford-Binet IV were statistically significant. It is apparent that the two tests measure similar, but not identical, concepts.
The Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R; Wechsler, 1989) was published because many of the items in the earlier version, as well as the norms, were outdated. Changes in American culture, such as more mothers working outside the home, more singleparent famdies, preschool education, the impact of television, etc. are among the reasons prompting the development of the WPPSI-R. The 1967 WPPSI was designed for children 4 yr., 0 mo. to 6 yr., 6 mo.; the age range for the WPPSI-R is 3 yr., 0 mo. to 7 yr., 3 mo. The downward extension of age will enable the WPPSI-R to be used to satisfy the federal mandate for screening for intellectual deficits for early childhood handicapped programs which extend to children as young as 3 yr., 0 mo. Other major differences are the introduction of a new subtest (Object Assembly) and the downgrading of Animal House (now called Animal Pegs) to an optional subtest. Numerous item changes have occurred to make the test more appropriate for the new age range and to update the items and improve their quality. Given the emphasis now being placed on early childhood education for handicapped children and because the number of tests for younger children is limited, the WPPSI-R may be much more important than its predecessor; therefore, the validity of the revision is of paramount importance. The Stanford-Binet Intelligence Scale: Fourth Edition (Stanford-Binet IV; Thorndike, Hagen, & Sattler, 1986a) has become one of the major tools used in the evaluation of young children. Wechsler (1989) reported a correlation of .74 between the WPPSI-R Full Scale I Q and the Stanford-Binet IV Composite Standard Age Score; he also reported a correlation of .87 between the 1967 WPPSI and the WPPSI-R. Wechsler (1967) also stated that the 'Address correspondence to H. H. Carvajal, Division of Psychology, Emporia State University, 1200 Commercial, Emporia, KS 66801-5087.
24
H. H. CARVAJAL, E T A L
correlation between the 1960 Stanford-Binet and the original WPPSI was .74. Thorndike, Hagen, and Sattler (1986b) reported a correlation of .80 between the Composite Standard Age Score of Stanford-Binet IV and the 1967 WPPSI Full Scale IQ. According to the correlations reported in the manuals, the tests are measuring similar, but not identical, constructs. Often authors' proofs of validity are based on limited and nonrepresentative samples; therefore, studies of concurrent criterion-related validity which are independent of the authors must prove the tests' validity prior to general usage. To do this, as well as to check on the appropriateness of the WPPSI-R for the new age range, the following study was conducted. METHOD Fifty-one children (27 boys, 24 girls) ranging in age from 3 yr., 6 mo. to 7 yr., 3 mo. (M = 5.7; SD = 1.0) who attended either preschool, kindergarten, first, or second grade in an elementary school in a midwestern community of 27,000 were tested with the Stanford-Binet IV and the WPPSI-R. With the exception of one Hispanic boy and one American-born Chinese boy, all of the children were Caucasian and would be considered middle-class. Four second-year graduate students who had successfully completed testing courses in their school or clinical psychology programs administered the tests in a counterbalanced sequence between October 1 and December 14, 1990. AU tests were given under standard conditions, and standardized procedures were followed The complete WPPSI-R was given; the WPPSI-R yields three intelligence quotients (IQs): Verbal, Performance, and Full Scale. Each has a mean of 100 and a standard deviation of 15. Those Stanford-Binet IV subtests appropriate for each child's age were given. The Stanford-Binet IV yields scores for four areas: Verbal Reasoning, Abstract/Visual Reasoning, Quantitative Reasoning, and Short-term Memory; there is also a composite score. The mean and standard deviation of the Area and Composite Standard Age Scores (SAS) are 100 and 16, respectively. RESULTSAND DISCUSSION Descriptive statistics are reported in Table 1. With the exception of the Stanford-Binet IV Quantitative Reasoning mean, all of the Stanford-Binet IV and WPPSI-R means were larger than means of the norm groups. I n contrast to the means, all of the standard deviations were smaller than the norm groups. F tests for the homogeneity of variances (Winer, Brown, & Michels, 1991) were performed [critical F(infinity, 51) = 1.451, and the standard deviations of the Verbal Reasoning, Abstract/Visual Reasoning, and composite scores of the Stanford-Binet IV were significantly lower, indicating a sample more homogeneous on these characteristics than the normative groups.
WPPSI-R
25
AND STANFORD-BINET IV TABLE 1
DESCRIPITVE STATISTICS AND PEARSON CORRELATIONS: WPPSI-R AND
STANFORD-BINET IV STANDARD AGESCORES( N = 51)
Test 1. WPPSI-R Verbal I Q 2. WPPSI-R Performance I Q 3. WPPSI-R Full Scale IQ 4. Binet Verbal Reasoning SAS 5. Binet Abstract/Visual SAS 6 . Binet Quantitative Reasoning SAS 7 . Binet Short-term Memory SAS 8. Binet Composite SAS *p
RELATIONSHIPS BETWEEN SCORES O N WECHSLER PRESCHOOL A N D PRIMARY SCALE OF INTELLIGENCE-REVISED A N D STANFORD-BINET I V ' HOWARD H . CARVAJAL, JAMES E PARKS, KIMBERLY J. BAYS, ROBERTA. LOGAN, CAROL I. LUJANO, GREGORY L. PAGE, AND KENNETH A. WEAVER Emporia State University Summary.-The Wechsler Preschool and Primary Scale of Intelligence-Revised and the Stanford Binet-Intelligence Scale: Fourth Edition were given to 5 1 preschool, kindergarten, first, and second p a d e students. Twelve of 15 Pearson correlations between Wechsler IQs and composite and area scores of the Stanford-Binet IV were statistically significant. It is apparent that the two tests measure similar, but not identical, concepts.
The Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R; Wechsler, 1989) was published because many of the items in the earlier version, as well as the norms, were outdated. Changes in American culture, such as more mothers working outside the home, more singleparent famdies, preschool education, the impact of television, etc. are among the reasons prompting the development of the WPPSI-R. The 1967 WPPSI was designed for children 4 yr., 0 mo. to 6 yr., 6 mo.; the age range for the WPPSI-R is 3 yr., 0 mo. to 7 yr., 3 mo. The downward extension of age will enable the WPPSI-R to be used to satisfy the federal mandate for screening for intellectual deficits for early childhood handicapped programs which extend to children as young as 3 yr., 0 mo. Other major differences are the introduction of a new subtest (Object Assembly) and the downgrading of Animal House (now called Animal Pegs) to an optional subtest. Numerous item changes have occurred to make the test more appropriate for the new age range and to update the items and improve their quality. Given the emphasis now being placed on early childhood education for handicapped children and because the number of tests for younger children is limited, the WPPSI-R may be much more important than its predecessor; therefore, the validity of the revision is of paramount importance. The Stanford-Binet Intelligence Scale: Fourth Edition (Stanford-Binet IV; Thorndike, Hagen, & Sattler, 1986a) has become one of the major tools used in the evaluation of young children. Wechsler (1989) reported a correlation of .74 between the WPPSI-R Full Scale I Q and the Stanford-Binet IV Composite Standard Age Score; he also reported a correlation of .87 between the 1967 WPPSI and the WPPSI-R. Wechsler (1967) also stated that the 'Address correspondence to H. H. Carvajal, Division of Psychology, Emporia State University, 1200 Commercial, Emporia, KS 66801-5087.
24
H. H. CARVAJAL, E T A L
correlation between the 1960 Stanford-Binet and the original WPPSI was .74. Thorndike, Hagen, and Sattler (1986b) reported a correlation of .80 between the Composite Standard Age Score of Stanford-Binet IV and the 1967 WPPSI Full Scale IQ. According to the correlations reported in the manuals, the tests are measuring similar, but not identical, constructs. Often authors' proofs of validity are based on limited and nonrepresentative samples; therefore, studies of concurrent criterion-related validity which are independent of the authors must prove the tests' validity prior to general usage. To do this, as well as to check on the appropriateness of the WPPSI-R for the new age range, the following study was conducted. METHOD Fifty-one children (27 boys, 24 girls) ranging in age from 3 yr., 6 mo. to 7 yr., 3 mo. (M = 5.7; SD = 1.0) who attended either preschool, kindergarten, first, or second grade in an elementary school in a midwestern community of 27,000 were tested with the Stanford-Binet IV and the WPPSI-R. With the exception of one Hispanic boy and one American-born Chinese boy, all of the children were Caucasian and would be considered middle-class. Four second-year graduate students who had successfully completed testing courses in their school or clinical psychology programs administered the tests in a counterbalanced sequence between October 1 and December 14, 1990. AU tests were given under standard conditions, and standardized procedures were followed The complete WPPSI-R was given; the WPPSI-R yields three intelligence quotients (IQs): Verbal, Performance, and Full Scale. Each has a mean of 100 and a standard deviation of 15. Those Stanford-Binet IV subtests appropriate for each child's age were given. The Stanford-Binet IV yields scores for four areas: Verbal Reasoning, Abstract/Visual Reasoning, Quantitative Reasoning, and Short-term Memory; there is also a composite score. The mean and standard deviation of the Area and Composite Standard Age Scores (SAS) are 100 and 16, respectively. RESULTSAND DISCUSSION Descriptive statistics are reported in Table 1. With the exception of the Stanford-Binet IV Quantitative Reasoning mean, all of the Stanford-Binet IV and WPPSI-R means were larger than means of the norm groups. I n contrast to the means, all of the standard deviations were smaller than the norm groups. F tests for the homogeneity of variances (Winer, Brown, & Michels, 1991) were performed [critical F(infinity, 51) = 1.451, and the standard deviations of the Verbal Reasoning, Abstract/Visual Reasoning, and composite scores of the Stanford-Binet IV were significantly lower, indicating a sample more homogeneous on these characteristics than the normative groups.
WPPSI-R
25
AND STANFORD-BINET IV TABLE 1
DESCRIPITVE STATISTICS AND PEARSON CORRELATIONS: WPPSI-R AND
STANFORD-BINET IV STANDARD AGESCORES( N = 51)
Test 1. WPPSI-R Verbal I Q 2. WPPSI-R Performance I Q 3. WPPSI-R Full Scale IQ 4. Binet Verbal Reasoning SAS 5. Binet Abstract/Visual SAS 6 . Binet Quantitative Reasoning SAS 7 . Binet Short-term Memory SAS 8. Binet Composite SAS *p
