The purpose of this study was to investigate differences in Texas Teacher Appraisal System (TTAS) scores when considering the scores of the first four individual domains (Instructional Strategies, Management and Organization, Presentation of Subject Matter, and Learning Environment), the sum of the scores of Domains I through IV, and the overall summary performance score for teachers in a large school district over a period of 2 years. Specifically, scores between appraiser types (primary or second), levels (elementary or secondary), years (1988-1989 or 1989-1990), and apraisal periods (first or second) were investigated. The subjects were teachers in a large school district in Texas for the school years 1988-1989 (N=1,159) and 1989-1990 (N=1,207). All teachers were evaluated with the TTAS by a certified appraiser, following the procedures mandated by the State Board of Education. Campus administrators or central office personnel conducted all observations. MANOVA and ANOVA were performed to examine differences in the scores of various subgroups of teachers. In general, results showed that significantly higher scores were awarded by the primary appraisers and that elementary teachers received higher scores than secondary teachers. In addition, scores increased from the first appraisal period to the second appraisal period and from year to year. The results of this study suggest the need for additional research on the validity of the instrument, staff development for teachers and appraisers, and modifications to the instrument or scoring procedures to make TTAS scores meaningful. (Author)