PREDICTING INTEREST OF A USER OF A SOCIAL NETWORKING SERVICE IN A CONTENT ITEM

The subject matter of this specification can be implemented in, among other things, a computer-implemented method including determining an affinity score representing an affinity of a user with respect to a contact of the user, wherein the affinity score is an indication of a strength of a relationship between the user and the contact, determining an engagement score of the user with respect to the contact, wherein the engagement score in an indication of a probability of the user engaging with a content item associated with the contact, determining an interest score of the user with respect to the contact based on the affinity score and the engagement score and providing a plurality of content items posted by the contact display in an activity stream, the content items being ordered based on the interest score. Other aspects can include corresponding systems, apparatus and computer program products.