When middle school students learn science content with graphs, the graphing and science knowledge may be mutually reinforcing: understanding the science content may help students interpret a related graph, and information from a graph may illustrate a scientific concept. We examine this relationship between graphing and science by studying how students learn from interactive computer models with accompanying data graphs. The computer models provide an animated simulation that illustrates an unobservable phenomenon, while the data graph tracks one or more quantities over time. This ordering study, on middle school students learning about photosynthesis, indicates that engaging with novel graph concepts helped students interpret their data as they experimented with the computer model. The study also provided some support for the opposite direction: experimenting with the model first helped students make sense of the graphs.