1. One or more computer-readable media having computer-executable instructions embodied thereon that, when executed by a computing system having a processor and memory, cause the computing system to perform a method for personalizing a language model for a particular target user based on user history information, the method comprising: receiving usage history information for a target user from one or more sources; parsing the usage history information to identify one or more of an entity or a user action; mapping the one or more of the entity or the user action to a knowledge source, thereby creating a personalized knowledge source; and utilizing the personalized knowledge source to personalize a language model for the target user.