14. The system of claim 5 , wherein the item search engine further comprises machine readable instructions that cause the at least one computing device to at least send the network page to the client.
5. A system, comprising: at least one computing device comprising a processor and a memory; and an item search engine comprising machine readable instructions stored in the memory that, when executed by the processor, cause the at least one computing device to at least: determine that a search query string includes a plurality of application keywords describing a make, a model, and a year of an automobile; identify a result set of automotive items from a catalog of items according to the application keywords, the result set of automotive items being compatible with the automobile; rank the result set of automotive items according to customer behavior data indicating selections of automotive items by a plurality of other users who also searched for automotive items compatible with the automobile, wherein ranking the result set of automotive items is configured to surface in the result set a particular automotive item that is associated with a defect in the automobile; determine an inferred keyword according to the automobile and additional customer behavior data that indicates a plurality of sales of automotive items to the plurality of other users; determine a non-application keyword specified in the search query string; and identify a subset of the result set of automotive items according to the inferred keyword and the non-application keyword.