Abstract: The arrangement and selection of digital content to present to a user can be based at least in part upon probabilities of the user selecting to view more information and/or entering into a transaction with respect to instances of the content. For example, user behavior with respect to various items provided through a content provider can be determined in order to calculate a probability that a user was searching for a particular type of item for a given search. The user behavior can include historical action data, such as information that indicates items that were selected in response to a particular search and/or items that were purchased in response to a particular search. The historical action data can be analyzed to generate an index that indicates a likelihood that the search was intended for a particular type of product. Additionally, the historical data can be used to train language models that can be used to determine a probability of interest for a particular type of product for a given search.