This study investigated bias at the item level in six subtests of the California Achievement Tests (CAT). Variability of performance across all individual items of the CAT for fourth graders from three ethnic groups was examined. A two-factor (item scores and ethnicity) ANOVA procedure was used to examine the interaction between Anglo and Hispanic children and between Anglo and black subjects on individual test items of the subtests. Significant F-ratios for the Items x Groups interaction were further examined by using Bonerroni's post-hoc test for the purpose of identifying specific items reflecting cultural bias. A total of twenty-one items was identified as culturally biased. Of these items, sixteen were biased against Hispanics, three items were found to contain bias against blacks, and two items reflected bias against both Hispanic and black children. Of these twenty-one items identified as biased, eighteen belonged to four verbal subtests and three items are part of the two mathematics subtests. In addition to these items identified as being statistically biased, this study suggests that ethnocultural differences exist on overall performance levels between groups. For example, on the verbal subtests, there was a total of only three items on which Hispanic children scored higher than Anglo subjects, and only one item which reflected a better performance by black children than Anglo students. Higher performance levels by Anglo subjects were also noted on mathematic subtests, wherein Hispanic children scored higher on six items than their Anglo counterparts, and black subjects outperformed Anglo children on only one item. These data reflected a tendency of higher performance by Anglo students across all subtests when by an examination of the number of items passed or failed by members of each ethnic group was made. The examination of the verbal subtests additionally showed that Anglos passed sixty-five items, Hispanic children passed twenty-four items and thirty-two items were passed by black subjects. This trend continued on the mathematics subtests, where thirty-one items were passed by Anglo students and seventeen and fifteen items were passed by Hispanic and black children respectively. The findings of this study led to the conclusion that the majority of items on the CAT does not reflect evidence of cultural bias. There were, however, a limited number of items on which either Hispanic or black children out-performed their Anglo counterparts. Implications of these findings were discussed and recommendations were made for future studies to examine bias at the item level
