Patent attributes
Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a measure of quality for a resource. In one aspect, a method includes determining a seed score for each seed resource in a set. The seed score for a seed resource can be based on a number of resources that include a link to the seed resource and a number of selections of the links A set of source resources is identified. A source score is determined for each source resource. The source score for a source resource is based on the seed score for each seed resource linked to by the source resource. Source-referenced resources are identified. A resource score is determined for each source-referenced resource. The resource score for a source-referenced resource can be based on the source score for each source resource that includes a link to the source-referenced resource.