Query completions in the context of a user's own document

Methods, systems and apparatus are described herein that include receiving a partial query entered into a search field on a computing device, and data indicating a document presented on the computing device during entry of the partial query. The presented document has been edited by a user of the computing device. Search results are then obtained which identify respective lists of search results documents for corresponding candidate query completions in a set obtained for the partial query. Similarity scores are then calculated for candidate query completions based at least in part on a similarity between content in the displayed document and content in search result documents in the corresponding lists. One or more candidate query completions in the set are then selected as refined query completions for the partial query based at least in part on the similarity scores and provided for presentation by the computing device.