To ascertain the effect of a preschool program on the behavior of migrant children the Pre-Kindergarten Scale (PKS) was completed by teachers and teacher aides. In order to analyze the resulting data it was necessary to construct and validate the trait measures obtained from the scale. A sample of the ratings on 144 migrant children, subjected to a principal components factor analysis, provided four factors: Cognitive skills, self control, relationship with achievement model, and dependency. Factor coefficients were obtained for the 25 items based on four factors and applied to ratings on another sample of 153 migrant children. Trait scores for each rater were correlated with those of the other raters for a total of three multi-rater, multi-trait matrices. When these matrices were analyzed, cognitive skills, self control, and relationships with achievement model showed a convincing degree of convergent-discriminant validity. Dependency showed slightly less convincing validity. The findings support the overall validity of the four traits and have implications for future analysis of traits obtained from behavioral ratings. (LR)