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Sammon mapping of 1,203 base symbols (project ideas) in the Science Buddies recommender system, color coded by 32 different areas of science, enables us to visualize the history of user interactions with the system. Each base symbol is defined by 78 probabilities representing the three possible answers for each of the 26 questions in our science interest survey. Here, Sammon mapping has reduced those 78 dimensions to an estimate of just three arbitrary dimensions that we can plot in a 3-dimensional space. The distance between symbols (in arbitrary units) represents an estimate of their similarity or dissimilarity. Symbols with similar histories will be close together and symbols with dissimilar histories will be far apart. Bubble size scales with the popularity of the symbol in the historical record, larger size meaning that a larger number of students took actions indicating satisfaction with the item. (See “Defining a Lingua Franca to Open the Black Box of a Naïve Bayes Recommender” in Publications and Lectures.)