Abstract: A variation testing system environment for performing variation testing of web pages and applications is disclosed. Users requesting a view from a content provider are not randomly assigned to one of a plurality of variations of the view. Rather, a function is applied to each user's identifier in order to determine which variation of the view is provided to a client device of the user.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for distributing and presenting of electronic content. One method provides an enhanced ordering of ranked documents, in which one or more lists of documents that have been published in a web feed, a time that each document was published in the web feed, and a content-based ranking of a ranked subset of the documents are obtained, the documents collectively including ranked documents which are members of the ranked subset of the documents, and unranked documents which are not members of the ranked subset of the documents. Furthermore, a user interface is provided which displays links to a plurality of the ranked documents, ordered according to the content-based ranking, and which simultaneously displays links to a plurality of the unranked documents, ordered chronologically based on the time that each respective document was published in the web feed.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for distributing and presenting of electronic content. One method provides an enhanced ordering of ranked documents, in which one or more lists of documents that have been published in a web feed, a time that each document was published in the web feed, and a content-based ranking of a ranked subset of the documents are obtained, the documents collectively including ranked documents which are members of the ranked subset of the documents, and unranked documents which are not members of the ranked subset of the documents. Furthermore, a user interface is provided which displays links to a plurality of the ranked documents, ordered according to the content-based ranking, and which simultaneously displays links to a plurality of the unranked documents, ordered chronologically based on the time that each respective document was published in the web feed.