Attention and intelligence: The validity of the Star Counting Test.

The mechanisms underlying performance on the Star Counting Test (SCT) and its nomothetic span were investigated along with the relationships between working memory capacity, fluid intelligence (Gf), speed, and school achievement. The SCT is an attention test for children that requires the alternation of forward and backward counting. The test is based on A. D. Baddeley and G. J. Hitch's (1974) model of working memory in conjunction with D. A. Norman and T. Shallice's (1986) theory of central executive functioning. Tests were administered to 1,122 boys and 1100 girls in 4th grade from 111 Dutch schools. The SCT required flexible alternation, counting speed, and sustained effort. Factor analysis showed that the SCT forms one factor with other indicators of working memory capacity. There was also a strong association between working memory capacity and Gf. The two clearly differ, however, in their relation to speed. Attention and intelligence are important determinants of school achievement (Fraser, Walberg, Welch, & Hattie, 1987; Horn & Packard, 1985; Rowe, 1991). During this century, correlational studies have provided considerable insight into the structure of intelligence (e.g., Carroll, 1993). More recently, experimental researchers have identified some of the mechanisms underlying performance on specific intelligence tests (Butterfield, Nielsen, Tangen, & Richardson, 1985; Carpenter, Just, & Shell, 1990; Geary & Widaman, 1992; Steraberg, 1985). In contrast, in the field of attention there is still a gap between what Cronbach (1957) called the "two disciplines of psychology" (p. 671), the experimental and the correlational approach. In the present study, both approaches were used to investigate the construct validity of the Star Counting Test (SCT), an attention test for children (de Jong & Das-Smaal, 1990). First, the construct representation of the test, including its dimensionality and the mechanisms that are involved in test performance, was determined. Next, we examined the nomothetic span of the SCT by considering its relationships with working memory, intelligence, speed, and school achievement. In what follows, we first describe the theoretical background of the test, and subsequently, we consider its construct representation and nomothetic span.