Location-based place determination using online social networks

1. A method comprising, by one or more computing devices of an online social network:

receiving, from a mobile-client system of a first user of the online social network, geographic-location information associated with the mobile-client system;

identifying a plurality of candidate place-entities associated with the online social network that correspond to the geographic-location information, wherein each candidate place-entity is associated with a particular geographic location;

determining, for each candidate place-entity, a confidence score based on the geographic-location information associated with the mobile-client system and a location-probability distribution associated with the candidate place-entity, wherein the confidence score represents a probability that the first user is located at the candidate place-entity; and

sending, to the mobile-client system of the first user, information associated with one or more of the candidate place-entities having a confidence score above a threshold confidence score.

2. The method of claim 1 , wherein the geographic-location information comprises a latitude-longitude pair determined based on one or more signals received by the mobile-client system.

3. The method of claim 2 , wherein the geographic-location information further comprises an accuracy value associated with the latitude-longitude pair.

4. The method of claim 1 , wherein the geographic-location information comprises signal-information associated with one or more signals received by the mobile-client system, the signals comprising a Global Positioning System (GPS) signal, a Wi-Fi signal, a BLUETOOTH signal, a cellular signal, or a near field communication (NFC) signal.

5. The method of claim 4 , wherein the signal-information comprises a signal strength of one of the signals or an identifier of a device that sent one of the signals.

6. The method of claim 1 , wherein the geographic-location information comprises a check-in via the online social network by the first user.

7. The method of claim 1 , wherein the particular geographic location associated with each identified candidate place-entity is within a threshold distance of a geographic location of the mobile-client system.

8. The method of claim 1 , further comprising accessing a social graph comprising a plurality of nodes and a plurality of edges connecting the nodes, each of the edges between two of the nodes representing a single degree of separation between them, wherein the first user corresponds to a first node in the social graph and the plurality of candidate place-entities corresponds to a plurality of second nodes in the social graph, respectively.

9. The method of claim 8 , wherein the confidence score is further based on social-graph information associated with the first user.

10. The method of claim 8 , wherein the confidence score is further based on social-graph information associated with a second user of the online social network, the second user being within a threshold degree of separation from the first user.

11. The method of claim 1 , wherein:

the location-probability distribution associated with the candidate place-entity comprises a point, the point corresponding to the particular geographic location of the candidate place-entity; and

the confidence score is further based on a distance between the point and a geographic location of the mobile-client system.

12. The method of claim 1 , wherein:

the location-probability distribution associated with the candidate place-entity comprises a power-law distribution centered at a point, the point corresponding to the particular geographic location of the candidate place-entity; and

the confidence score is further based on a value of the power-law distribution at a geographic location of the mobile-client system.

13. The method of claim 1 , wherein:

the location-probability distribution associated with the candidate place-entity comprises a kernel density estimate corresponding to a probability density associated with the candidate place-entity; and

the confidence score is further based on a value of the kernel density estimate at a geographic location of the mobile-client system.

14. The method of claim 1 , wherein:

the location-probability distribution associated with the candidate place-entity comprises a polygon representing a shape of the candidate place-entity; and

the confidence score is further based on a geographic location of the mobile-client system with respect to the polygon.

15. The method of claim 1 , further comprising:

receiving, from the mobile-client system of the first user, a selection of one of the candidate place-entities sent to the mobile-client system of the first user; and

recalculating, based on the received selection, the location-probability distribution associated with one or more of the candidate place-entities sent to the mobile-client system of the first user.

16. The method of claim 1 , further comprising:

receiving a plurality of new geographic-location information associated with a new place-entity, the new geographic-location information sent by a respective plurality of other mobile-client systems associated with a respective plurality of other users of the online social network;

generating, in a social graph, a new social-graph node corresponding to the new place-entity, the social graph comprising a plurality of nodes and a plurality of edges connecting the nodes; and

creating an edge between the new social-graph node and each node associated with each of the plurality of other users.

17. The method of claim 1 , wherein the information sent to the mobile-client system of the first user comprises an advertisement associated with one of the candidate place-entities having the confidence score above the threshold confidence score.

18. The method of claim 1 , wherein the information sent to the mobile-client system of the first user comprises a suggestion to the first user to perform an action associated with one of the one or more candidate place-entities.

19. One or more computer-readable non-transitory storage media embodying software that is operable when executed to:

receive, from a mobile-client system of a first user of an online social network, geographic-location information associated with the mobile-client system;

identify a plurality of candidate place-entities associated with the online social network that correspond to the geographic-location information, wherein each candidate place-entity is associated with a particular geographic location;

determine, for each candidate place-entity, a confidence score based on the geographic-location information associated with the mobile-client system and a location-probability distribution associated with the candidate place-entity, wherein the confidence score represents a probability that the first user is located at the candidate place-entity; and

send, to the mobile-client system of the first user, information associated with one or more of the candidate place-entities having a confidence score above a threshold confidence score.

20. A system comprising: one or more processors; and a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to:

receive, from a mobile-client system of a first user of an online social network, geographic-location information associated with the mobile-client system;

identify a plurality of candidate place-entities associated with the online social network that correspond to the geographic-location information, wherein each candidate place-entity is associated with a particular geographic location;

determine, for each candidate place-entity, a confidence score based on the geographic-location information associated with the mobile-client system and a location-probability distribution associated with the candidate place-entity, wherein the confidence score represents a probability that the first user is located at the candidate place-entity; and

send, to the mobile-client system of the first user, information associated with one or more of the candidate place-entities having a confidence score above a threshold confidence score.