This study examines how teachers' frameworks for human development, curriculum, and mathematics influence how they interpret children's mathematical thinking. The teachers in the study were participants in a professional development project to help them implement cognitively-guided instruction (CGI) in their mathematics instruction. Data on teacher beliefs, interpretations of children's solutions to mathematics problems, and instructional decision making were gathered. Results suggest that teachers focus most frequently and very consistently on the curriculum framework. The increasing importance of the developmental framework appears to be due to the increased attention paid by teachers to the different kinds of solution strategies used by students. (Author/ASK)