Described is a system and method for presenting event information to a user and, if necessary, obtaining confirmation of different aspects (user, item, action) of the event. In some implementations, an event includes a user, an action, and an item. For example, an event may include a user picking an item from an inventory location, a user placing an item into a tote associated with the user, etc. if the aspects of the event cannot be determined with a high enough degree of confidence, a user interface may be generated and sent to the user requesting confirmation of one or more of the aspects of the event.