8. A system, comprising: a data processing apparatus; and a 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, for a query sequence, a word boundary likelihood that represents a likelihood that the query sequence terminates at a word boundary; determining, based on the word boundary likelihood, a time delay for delaying providing search results for the query sequence; determining that an amount of time since receipt of the query sequence exceeds the time delay, and in response: identifying search results responsive to the query sequence; and providing the identified search results.
8. A system, comprising: a data processing apparatus; and a 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, for a query sequence, a word boundary likelihood that represents a likelihood that the query sequence terminates at a word boundary; determining, based on the word boundary likelihood, a time delay for delaying providing search results for the query sequence; determining that an amount of time since receipt of the query sequence exceeds the time delay, and in response: identifying search results responsive to the query sequence; and providing the identified search results. 13. The system of claim 8 , wherein determining the time delay comprises determining that the word boundary likelihood exceeds a threshold and, in response, setting the time delay to a particular value.