A Technique for the Investigation of Cultural Differences.

A technique for detecting and studying item (or test) x group interactions independent of differences in level or dispersion of the groups is described. It involves construction of a scatter plot with two groups represented, one on each axis. Each point in the scatter plot represents the coordinates of a measure of a characteristic for one group plotted against a measure of the same characteristic for the other group; and the set of N points in the scatter plot represented the variables under study. The shape of the ellipse represents the degree to which the two groups in question share similar profiles. One method of analysis is to measure the departure of each point from the major axis of the ellipse and to study specific items that are most aberrant. Another is to calculate the variance associated with the item x interaction. Although the technique is not intended as a measure of item or test bias, it is useful in diagnosing cultural differences and comparing different types of groups. (Author/DJ)