A number of concerns have been raised by researchers regarding the use of models in science classrooms. Those concerns have largely been raised in studies involving interviews with students and teachers. In this article, I address issues that surfaced through my examination of classroom teaching episodes; two of these episodes and their associated issues are presented as a pair of vignettes. I offer a framework for reflecting on such issues that focuses on four key terms from a definition of models: "embody", "tools", "phenomena", and "characteristics". Preceding each vignette, the meaning of the term is unpacked, and following each vignette, that term is used to analyze the way model-related actions unfolded in the episode. This framework has the potential to allow teachers to better facilitate their students' use of models for investigating chemical phenomenon. This could endow students with the capacity to engage in more sophisticated modeling processes such as creating and analyzing their own models. (Contains 9 notes and 2 figures.)