This study provides an in-depth look into the implementation process of visualization-based tools for structuring collaborative problem solving (CPS) in the classroom. A visualization-based learning platform--the semantic diagram for structuring CPS in a real classroom was designed and implemented. Metafora, the preliminary vehicle of the semantic diagram, was integrated into the "Food and Nutrition" CPS curriculum in a fifth-grade science classroom in east China. Data of a teacher's and her students' activities from the CPS classroom were analyzed to understand how Metafora could be integrated into the CPS instructional process, what roles Metafora and the teacher played in the CPS project, and to what extent Metafora might have affected the teacher's instruction and the students' learning activities in the CPS classroom. Results showed that the semantic diagram could be integrated into the CPS classroom adaptively and flexibly, and that it was important to keep a balance between the role of the semantic diagram and the role of the teacher. Implications for semantic diagram design and implementation for structuring CPS in the classroom, as well as future work about the semantic diagram will be discussed.