The development of the Stanford Foreign Language Oral Skills Evaluation Matrix (FLOSEM), a rating scale for assessing communicative proficiency in foreign languages, is described. Information on the utility of the FLOSEM is presented based on the results of three studies. Oral proficiency measures were obtained by means of the FLOSEM from 573 high school students enrolled in beginning through advanced Japanese, Chinese, and Korean. Classroom foreign language teachers rated students' proficiency at the beginning and the end of the school year. Students also used the FLOSEM to rate their own proficiency in the target language. In addition to FLOSEM ratings, oral proficiency was also assessed for a subset of 132 students by means of the Classroom Oral Competency Interview (COCI), which is a brief 5-7 minute interview. Findings reveal that FLOSEM can be used for indexing growth in foreign language proficiency within and across instructional levels. Correlation between teachers' ratings and students' self-ratings on FLOSEM were high and statistically significant at all levels of instruction for all three languages. Correlation between proficiency ratings obtained on the FLOSEM and COCI were also high and statistically significant. These findings support the use of FLOSEM as a valid, reliable, and convenient measure of communicative proficiency available for use by foreign language teachers. Several figures and tables are used to display data. (Contains 18 references.) (Author/KFT)