Patent ID: 8533202

Claim:
A method comprising: storing a particular set of content items, wherein the particular set of content items comprises a plurality of content items; determining a candidate set of content items, wherein each content item in the candidate set of content items is from one or more of a plurality of sources; wherein content items in the particular set and the candidate set are associated with characteristics; for a first content item of the candidate set of content items, measuring a first diversity of characteristics in a first combination of the first content item, and the particular set of content items; wherein measuring the first diversity of characteristics accounts for a first plurality of characteristics including a particular characteristic, wherein diversity of the particular characteristic is weighed differently than diversity of at least one other characteristic in the first plurality of characteristics such that differences in the particular characteristic have a greater or lesser impact than differences in at least one other characteristic on the first diversity of characteristics; for a second content item of the candidate set of content items, measuring a second diversity of characteristics in a second combination of the second content item, and the particular set of content items; wherein measuring the second diversity of characteristics accounts for a second plurality of characteristics including the particular characteristic, wherein diversity of the particular characteristic is weighed differently than diversity of at least one other characteristic in the second plurality of characteristics such that differences in the particular characteristic have a greater or lesser impact than differences in at least one other characteristic on the second diversity of characteristics; adding the first content item to the particular set of content items in response to determining that the first diversity of characteristics is greater than at least the second diversity of characteristics; wherein the method is performed by one or more computing devices.