1. A computer-implemented method, comprising: receiving a plurality of first search results in a first presentation format, the first search results received from a first search engine, the first search results identified for a search query directed to the first search engine, the first search results having an associated order indicative of respective first quality scores that are used to rank the first search results; receiving one or more second search results in a second presentation format different from the first presentation format, the second search results received from a second search engine, the second search results identified for the search query directed to the second search engine, wherein the first search engine searches a first corpus of first resources, wherein the second search engine searches a second corpus of second resources, and wherein the first search engine and the second search engines are distinct from each other; obtaining a respective first quality score for a plurality of the first search results, the respective first quality score determined in relation to the corpus of first resources and obtaining a respective second quality score for each of the one or more second search results, each respective second quality score determined in relation to the corpus of second resources; and inserting one or more of the second search results into the order including decreasing one or more of the respective first quality scores by reducing a contribution of a scoring feature unique to the first search results and distinct from scoring features of the second search results so that the inserted second search results occur within a number of top-ranked search results in the order.