9. The system of claim 6 , wherein the instructions further comprise instructions to perform the operation of identifying one or more terms based on content in the displayed document, and wherein the similarity score for the given query completion is based at least in part on similarity between the given query completion and the one or more terms.
9. The system of claim 6 , wherein the instructions further comprise instructions to perform the operation of identifying one or more terms based on content in the displayed document, and wherein the similarity score for the given query completion is based at least in part on similarity between the given query completion and the one or more terms. 10. The system of claim 9 , wherein the terms include one or more terms representing a topic of the displayed document.