As part of the evaluation of the Elementary and Secondary Education Act (ESEA) Title I Migrant Program, this study investigated whether teacher judgment of oral language proficiency could be used as a covariate in analyzing the reading test scores of migrant children, so that their possible lack of English proficiency could be taken into account when considering their reading achievement. Teacher ratings of the oral English proficiency of 6,000 second, fourth, and sixth grade migrant children were obtained. Ten percent of these children were also given the MAT-SEA-CAL Oral Proficiency Tests, an individually administered test, which served as a validation of the teacher ratings. Structural equation modeling was used to estimate the relationships between the MAT-SEA-CAL test scores, reading scores on the Comprehensive Tests of Basic Skills, and teacher ratings. The findings indicated that teacher judgments may be used as a measure of migrant children's oral language proficiency and as a covariate in the analysis of reading test scores. However, the study only dealt with the use of teacher ratings for group, not individual, decisions; generalizations made on the basis of these results should consider this distinction. (Author/GDC)