1. A system, comprising: a data processing apparatus; and a non-transitory computer storage medium encoded with a computer program, the program comprising data processing apparatus instructions that when executed by the data processing apparatus cause the data processing apparatus to perform operations comprising: receiving from a client device a request for a search resource; providing to the client device in response to the request for the search resource, the search resource including interface instructions that cause the client device to generate a search interface that includes a query input field; receiving a first query suggestion request from a client device, the query suggestion request having been generated in response to a query input in the query input field; in response to the first query suggestion request, providing first query suggestions responsive to the first query suggestion request and starting a timer for search results responsive to one of the first query suggestions, the timer being set to expire after a time period; receiving subsequent query suggestion requests from the client device after the first query suggestion request, each subsequent query suggestion request having been generated in response to a query input in the query input field; in response to each subsequent query suggestion request: providing subsequent query suggestions responsive to the subsequent query suggestion request; determining if a prediction criterion is met, the prediction criterion being independent of a user selection of a subsequent query suggestion provided in response to one or more subsequent query suggestion requests and independent of receiving a completed query from the client device, the determining comprising: determining that the prediction criterion is met when the timer expires and the search results responsive to the one of the first query suggestions are also responsive to one of the subsequent query suggestions provided in response to a most recent query suggestion request; in response to determining that the prediction criterion is met, providing the search results to the client device; and in response to determining that the prediction criterion is not met, not providing the search results to the client device.