This paper describes a software tool, the Oncology Thinking Cap (OncoTCAP) and reports on our efforts to develop a novice user interface to simplify the task of describing biological models of cancer and its treatment. Oncology Thinking Cap includes a modeling tool for making relationships explicit and provide dynamic feedback about the interaction between cancer cell kinetics, treatments, and patient outcomes. OncoTCAP supports student learning by making normally invisible processes visible and providing a representational tool that can be used to conduct thought experiments. We also describe our novice interface and report the results of initial usability testing.