This article presents the results of an educational intervention program aimed at 21 first and second grade teachers in public schools, focused on improving their interactions in science courses. The program included a group workshop, four cycles of classroom observation and individual coaching on the empirical cycle, as well as their interactions within the classroom. The design was quasi-experimental and based on repeated measures using the “CLASS” observation system, which analyzes classroom interactions in three different domains: emotional support, classroom organization and pedagogical support. The results show improvement in: negative environment, teacher sensitivity, productivity, concept development, quality of feedback and language modeling. The relevance of individual support based on teachers' observations also stands out.