YCAT-2

The YCAT-2 was normed on a representative sample of 846 children representing 25 states and 226 different zip codes. Reliability was studied using coefficient alpha, test–retest, and interscorer procedures. The average coefficient alpha for the full normative sample ranges from .85 to .95 for the subtests and is .97 for the overall composite.

Extensive validity evidence of the YCAT-2 is provided for content-description validity, criterion-prediction validity, and construct-identification validity. Content-description validity was established through careful selection of items, curricula review, conventional item analysis, as well as an analyses of test floors, ceiling, and item gradients, as well as differential item functioning to limit bias. Criterion prediction-validity was established by correlating YCAT-2 scores with the Woodcock-Johnson III Tests of Achievement and the Test of Language Development: Primary–Fifth Edition; comparing means and standard deviations between the YCAT-2 and criterion tests; and computing sensitivity, specificity, and ROC/AUC statistics. Construct-identification validity was established by studying the relationship of the YCAT-2 to age, reading, language, and intelligence; the ability of the YCAT-2 to differentiate between groups of students known to exhibit below-average academic achievement; and the factorial fit of the subtests to the construct in the test model (i.e., academic achievement).