The Bilingual Reading Study employs several measures of oral language proficiency: (1) a standardized oral language proficiency test, the Language Assessment Scales (LAS); (2) teacher ratings on the Student Operational Language Assessment Scale (SOLA); (3) teacher ratings on the Southwest Educational Development Laboratory (SEDL) Oral Language Proficiency Scale (OLPS); and (4) an ethnographic verification of each child's linguistic capability based on audio tapes of the child in the classroom, on the playground, and at home. In this paper, the reliability and distribution of responses for each measure is presented, followed by a discussion of the relations among the various measures. (BW)