Identifying unexpected relationships in a social networking system

A non-transitory computer-readable storage medium storing computer-executable instructions, the instructions, when executed by a processor, cause the processor to perform steps comprising:

• storing, by a social networking system, data representing a social graph comprising objects of the social networking system and connections describing relationships among the objects, the objects comprising a plurality of user profile objects representing users of the social networking system and a plurality of content objects,
• identifying a target object, the target object connected to some of the plurality of user profile objects in the social graph;
• identifying one or more pairs of user profile objects that are connected to the target object, the data representing the social graph indicating that the user profile objects in each pair are connected to each other in the social graph;
• determining, for each of the identified pairs, a measure of unexpectedness with respect to the target object, the measure of unexpectedness indicative of a likelihood that the identified pair being connected is unexpected to a target user of the social networking system who is represented by the target object in the social graph, the determining comprising:
• for each identified pair having a first identified object and a second identified object:
• (i) identifying a first subset of the plurality of user profile objects that are connected to both the first identified object and the target object;
• (ii) identifying a second subset of the plurality of user profile objects that are connected to both the second identified object and the target object,
• (iii) identifying a third subset of the plurality of user profile objects that are connected to the first identified object, the second identified object, the target object;
• (iv) determining the measure of unexpectedness as a value that is positively related to both a first number of objects in the first subset and a second number of objects in the second subset and that is inversely related to a third number of objects in the third subset;
• determining, for each of the identified pairs, whether the identified pair belongs to a false positive based on determining whether a content object in the social graph is connected to the first identified object, the second identified object and the target object;
• removing one or more of the identified pairs that are determined as false positives from selection;
• selecting one of the identified pairs based on the measure of unexpectedness with respect to the target object;
• selecting a particular content item associated with the selected pair;
• and
• transmitting the particular content item to the target user who is represented by the target object in the social graph.