15. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: identifying a search query, the search query including one or more terms; determining that one or more terms in the search query are associated with a domain; receiving ranked search results responsive to the search query, the search results having a ranked order and including at least a first and a second search result each associated with the domain, wherein the second search result has a lower ranking in the ranked order than the first search result, and the second search result is not adjacent to the first search result in the ranked order; determining to group search results associated with the domain based at least on one of (i) a genericness or (ii) a diversity of the search results; in response to the determining, reordering the search results comprising: grouping a number of search results associated with the domain together to generate a new ranking, including promoting the lower-ranked second search result associated with the domain to be ranked adjacent to the first search result associated with the domain, and reordering the search results by the new ranking, wherein the first and second search results are adjacent in the new ranking, and the second search result is adjacent in the new ranking to a third search result associated with a different domain; and providing the reordered search results for presentation.
15. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: identifying a search query, the search query including one or more terms; determining that one or more terms in the search query are associated with a domain; receiving ranked search results responsive to the search query, the search results having a ranked order and including at least a first and a second search result each associated with the domain, wherein the second search result has a lower ranking in the ranked order than the first search result, and the second search result is not adjacent to the first search result in the ranked order; determining to group search results associated with the domain based at least on one of (i) a genericness or (ii) a diversity of the search results; in response to the determining, reordering the search results comprising: grouping a number of search results associated with the domain together to generate a new ranking, including promoting the lower-ranked second search result associated with the domain to be ranked adjacent to the first search result associated with the domain, and reordering the search results by the new ranking, wherein the first and second search results are adjacent in the new ranking, and the second search result is adjacent in the new ranking to a third search result associated with a different domain; and providing the reordered search results for presentation. 16. The system of claim 15 , wherein determining that one or more terms in the search query are associated with a domain comprises determining that a term of the one or more terms of the search query is a domain name associated with the domain.