Methods, systems, and apparatus are described that include receiving a sequence of one or more characters representing a first partial query entered into a search field on a computing device. A first list of query completions for the first partial query is provided for display on the computing device. One or more additional characters are then entered into the search field, where the sequence of characters and the additional characters cumulatively represent a second partial query. A second list of query completions are then obtained for the second partial query, and one or more query completions appearing in the first and the second lists are identified. Demotion scores for the identified query completions are then calculated which are used to demote the identified query completions to a lesser position within the second list, thereby forming a refined second list for display on the computing device.