Validation of the Kaufman Assessment Battery for Children with a sample of preschool children

The validity of the Kaufman Assessment Battery for Children (K-ABC) (Kaufman & Kaufman, 1983) was investigated with a sample of preschool-age children. The sample consisted of 50 subjects aged 21/2 through 4 who were distributed roughly equally by age, sex, and race according to the 1980 census. The validity of the K-ABC was examined using the Slosson Intelligence Test (SIT) (Slosson, 1982) and the Classroom Behavior Inventory-Preschool Form (CBI) (Schaefer & Edgerton, 1978) as criterion measures. The SIT and CBI-Preschool Form Verbal Intelligence Scale were found to correlate significantly (p<.01) with the global scales of the K-ABC. The K-ABC did not differentiate between age or sex groups, but blacks scored lower than whites. The findings are supportive of previous validity studies (Kaufman & Kaufman, 1983) and two-factor theories of intelligence (e.g., Das, Kirby, & Jarman, 1975).     

Concurrent and predictive validity of the WISC-R,McCarthy Scales,Woodcock-Johnson,and academic achievement

Twenty-six normal first-grade children (M = 7.0 years) were administered the WISC-R, the McCarthy Scales, and the Woodcock-Johnson Scales of Cognitive Ability. Two years later, their levels of academic achievement were determined by way of the WRAT and global teacher ratings of classroom performance. Pearson intercorrelations among the summary indices of the three intellectual measures were significant and uniformly high (rang. 77-.95). Correlations between first-grade ability scores and third-grade achievement measures also were significant (range .64-.90), suggesting strong predictive validity for each of the cognitive instruments. Though not significantly so, the correlations between the Woodcock-Johnson and achievement tended to be the highest. The results indicate that all three intellectual measures are appropriate for predicting later academic achievement in young school-aged children.     

Recategorized WISC-R score patterns of older and younger referred Tlingit Indian children

This study investigated patterns of Bannatyne's recategorized WISC-R scores of 146 predominantly Tlingit Indian children who were referred for psychoeducational testing. The students were divided into two groups, ages 6 through 10 and 11 through 16, in order to investigate patterns that occurred at each level and to investigate the proportions that exhibited a typically “Indian” pattern: Spatial > Sequential > Conceptual and Acquired Knowledge. As a group, the older children displayed an Indian pattern, but the younger children displayed a different one: Spatial > Conceptual and Sequential > Acquired Knowledge. Both groups, however, displayed a significantly greater proportion of children with an Indian pattern than would be expected by chance. A considerable number of individuals from both groups attained significant differences among scores in the Indian direction.     

The law of one price,noise and “irrational exuberance”: the auction market for Picasso prints

We use prices realized for Picasso prints at auctions worldwide, as well as the 100 prints that comprise his Vollard Suite, to test the law of one price: the proposition that identical art objects sold contemporaneously should command the same price regardless of the auction house or geographic region where the sale takes place. Picasso is the most prolific printmaker of the twentieth century and, from 1977 to 2004, his prints appreciated in price significantly faster than the prints of modern masters as a whole. We find that Picasso prints sold in the United States command higher prices than in Europe. However, prices realized at Sotheby’s in New York are no longer higher than at Christie’s in New York, nor at Kornfeld than at other auction houses. We find evidence of “irrational exuberance” in the transitory nature of the extraordinary prices realized for the Picasso prints included in the 1997 sale of the collection of Victor and Sally Ganz at Christie’s in New York. More generally, we find substantial noise in auction outcomes, a result well known to savvy auction goers.