1. A method comprising, by one or more computing devices: accessing event information associated with an event listing; calculating one or more category probabilities for the event listing using one or more categorization models, respectively, each categorization model calculating a category probability based at least in part on the event information associated with the event listing, each category probability corresponding to a category, the category probability being equal to the probability that the event listing falls within the category; for each category probability greater than or equal to a threshold probability, associating with the event listing the category corresponding to the category probability; and displaying one or more of the categories associated with the event listing to a user.