8. 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: receiving a search query; obtaining search results that satisfy the search query, wherein the search results identify a plurality of web pages, wherein each web page is a web page on a corresponding website of a plurality of websites; computing a respective global ranking score for each website of the plurality of websites, wherein the global ranking score represents an indication of relevance of the website to the search query relative to other websites of the plurality of websites; computing an onsite ranking score for each of the plurality of web pages, wherein the onsite ranking score is computed from onsite data that is controlled by a webmaster or a developer of the corresponding website for the web page, wherein the onsite ranking score represents an indication of relevance of the web page as responsive to the search query relative to other web pages within the corresponding web site; selecting, as a representative web page for a particular website from among a plurality of web pages for the particular website, a particular web page having a highest onsite ranking score among the plurality of web pages for the particular website; comparing the onsite ranking score for the representative web page to the global ranking score for the particular website; determining that the onsite ranking score for the representative web page is not consistent with the global ranking score for the particular website; in response to determining that the onsite ranking score for the representative web page is not consistent with the global ranking score for the particular website, assigning a new global ranking score for the particular website including modifying the global ranking score for the particular website; computing a combined ranking score for each web page of the plurality of web pages including combining a respective global ranking score for a website associated with the web page and an onsite ranking score for the web page, including using the new global ranking score for the particular website when computing the combined ranking score for web pages on the particular website; and ranking the search results according to the combined ranking scores computed for respective web pages identified by the search results.
13. The system of claim 8 , wherein the global ranking score for the particular website is based on a frequency that a search result identifying a web page on the website has been selected by users that submitted the search query.