Patent Publication Number: US-2018052906-A1

Title: Systems and methods for recommending content items

Description:
FIELD OF THE INVENTION 
     The present technology relates to the field of content provision. More particularly, the present technology relates to techniques for recommending content items. 
     BACKGROUND 
     Today, people often utilize computing devices (or systems) for a wide variety of purposes. Users can use their computing devices to, for example, interact with one another, access content, share content, and create content. In some cases, content items can include postings from members of a social network. The postings may include text and media content items, such as images, videos, and audio. The postings may be published to the social network for consumption by others. 
     Under conventional approaches, a user may navigate to or be presented with various content items in a social network. The content items can come from pages associated with members of the social network. In some instances, the content items may be of high interest to the user. If the user expresses interest in a particular content item, the social network may attempt, based on the content item, to provide to the user additional content items that would also be of interest to the user. Providing such additional content items can enhance the user experience and may help realize the full potential of the social network. Unfortunately, attempts to provide such additional content items and to maintain a high level of interest from the user often fail. The growing size of social networks can also pose problems with respect to the goal of providing content items of high interest to the user. As available content grows in amount, in theory, the likelihood of finding more content items of high interest to the user should increase. However, in practice, the quality of randomly chosen content generally decreases while the specificity and/or quality of relevant content increases. 
     SUMMARY 
     Various embodiments of the present disclosure can include systems, methods, and non-transitory computer readable media configured to determine one or more geographic clusters that each correspond to a respective portion of a geographic region, each geographic cluster representing a neighborhood that includes a set of places which users residing in the neighborhood tend to frequently visit. A determination can be made that a user is located in a portion of the geographic region that corresponds to a first geographic cluster. At least one content item can be provided to be presented to the user, the content item being associated with the first geographic cluster. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to generate at least one chunk that represents a portion of a geographic region, obtain data describing a set of places in the chunk that have been visited by users of the social networking system, each place being associated with a respective geographic location, and generate at least one geographic cluster for the chunk based at least in part on a spectral clustering of the data describing the set of places that have been visited by the users. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to generate a similarity matrix that describes a respective pairwise cosine similarity between each place in the chunk. 
     In an embodiment, a cosine similarity between a first place and a second place is determined based at least in part on a number of users that checked-in at both the first place and the second place. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to determine a threshold amount of overlap between a first geographic cluster and a second geographic cluster and cause the first geographic cluster and the second geographic cluster to be merged or split based at least in part on one or more criteria. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to determine that the user performed a check-in through the social networking system at a place that corresponds to the first geographic cluster. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to associate at least one page with the first geographic cluster and provide the at least one page as a recommendation to the user. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to determining that a geographic centroid associated with the page corresponds to the first geographic cluster. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to determining that a threshold number of users have liked the at least one page, wherein the users reside in the portion of the geographic region that corresponds to the first geographic cluster. 
     In an embodiment, the systems, methods, and non-transitory computer readable media are configured to associate at least one suggestion with the first geographic cluster and provide the at least one suggestion to be presented to the user. 
     It should be appreciated that many other features, applications, embodiments, and/or variations of the disclosed technology will be apparent from the accompanying drawings and from the following detailed description. Additional and/or alternative implementations of the structures, systems, non-transitory computer readable media, and methods described herein can be employed without departing from the principles of the disclosed technology. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example system including an example page module, according to an embodiment of the present disclosure. 
         FIG. 2  illustrates an example of a geographic clustering module configured to generate geographic clusters, according to an embodiment of the present disclosure. 
         FIG. 3  illustrates an example of a page recommending module configured to recommend pages, according to an embodiment of the present disclosure. 
         FIG. 4  illustrates an example diagram of a geographic region that has been segmented into geographic clusters, according to an embodiment of the present disclosure. 
         FIG. 5  illustrates an example process for generating recommendations, according to an embodiment of the present disclosure. 
         FIG. 6  illustrates a network diagram of an example system including an example social networking system that can be utilized in various scenarios, according to an embodiment of the present disclosure. 
         FIG. 7  illustrates an example of a computer system or computing device that can be utilized in various scenarios, according to an embodiment of the present disclosure. 
     
    
    
     The figures depict various embodiments of the disclosed technology for purposes of illustration only, wherein the figures use like reference numerals to identify like elements. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated in the figures can be employed without departing from the principles of the disclosed technology described herein. 
     DETAILED DESCRIPTION 
     Approaches for Recommending Content Items 
     Today, people often utilize computing devices (or systems) for a wide variety of purposes. Users can use their computing devices to, for example, interact with one another, access content, share content, and create content. In some cases, content items can include postings from members of a social networking system. The postings may include text and media content items, such as images, videos, and audio. The postings may be published to the social networking system for consumption by others. 
     Under conventional approaches, a user may navigate to or be presented with various content items in a social network. The content items can come from pages associated with members of the social network. In some instances, the content items may be of high interest to the user. If the user expresses interest in a particular content item, the social network may attempt, based on the content item, to provide to the user additional content items that would also be of interest to the user. Providing such additional content items can enhance the user experience and may help realize the full potential of the social network. Unfortunately, attempts to provide such additional content items and to maintain a high level of interest from the user often fail. The growing size of social networks can also pose problems with respect to the goal of providing content items of high interest to the user. As available content grows in amount, in theory, the likelihood of finding more content items of high interest to the user should increase. However, in practice, the ability to identify content items of high interest to the user can be complicated by the sheer volume of content. Accordingly, such conventional approaches may not be effective in addressing these and other problems arising in computer technology. 
     An improved approach rooted in computer technology overcomes the foregoing and other disadvantages associated with conventional approaches specifically arising in the realm of computer technology. In various embodiments, page recommendations can be generated for users of a social networking system. A user can interact with a page in various ways and such interactions can result in the user forming a connection with the page. For example, a page may correspond to some type of subject matter (e.g., a business, topic, location, user, etc.). Users of the social networking system can navigate to the page to learn more about the subject matter as well as access and/or post content through the page. Users have the option to form a connection, or be associated, with the page, for example, by “liking” the page (e.g., selecting a “like” option through the social networking system) or by becoming a “fan” the page (e.g., selecting a “fanning” option through the social networking system). In this example, a user can form a connection with the page by performing actions such as visiting the page, fanning the page, and/or posting through the page, for example. 
     In various embodiments, page recommendations can be made based, in part, on geographic regions that have been clustered. That is, in some embodiments, each geographic cluster can define some geographic boundary that is determined to correspond to a respective “neighborhood,” e.g., a social community in which residents tend to frequently interact and/or visit places (e.g., geographic locations, points of interests such as restaurants, coffee shops, etc.). In some instances, the geographic boundary of a geographic cluster can be visualized using a convex hull. In some embodiments, such geographic clusters may be determined, in part, from user location data that is provided to a social networking system. In one example, the user location data can indicate geographic locations (e.g., places) at which a user has traveled and/or checked-in as well as a corresponding time stamp. In some embodiments, such geographic clusters may be determined, in part, from locations (or pseudo-locations) that are derived, or inferred, for users. Such pseudo-locations may be determined, for example, by analyzing geographic locations at which users have traveled and/or checked-in. In general, a check-in can be performed when a user that is operating a computing device selects a check-in option through a software application (e.g., social networking application) running on the computing device. Upon selecting the check-in option, the software application can determine the geographic location of the computing device (e.g., latitude and longitude coordinates determined from GPS data) and may associate that geographic location with a place (e.g., point of interest). In some instances, the user&#39;s check-in at the point of interest can be posted and/or broadcast as a status update to other users of the social networking system. In various embodiments, places that are similar can be determined from the user location data (e.g., check-in data), for example, based on a cosine similarity. A graph that describes the respective similarities between places can then be used as input for a clustering algorithm (e.g., spectral clustering) to generate the geographic clusters. 
       FIG. 1  illustrates an example system including an example page module  102 , according to an embodiment of the present disclosure. As shown in the example of  FIG. 1 , the page module  102  can include a geographic clustering module  104  and a page recommending module  106 . In some instances, the example system  100  can include at least one data store  108 . The components (e.g., modules, elements, etc.) shown in this figure and all figures herein are exemplary only, and other implementations may include additional, fewer, integrated, or different components. Some components may not be shown so as not to obscure relevant details. 
     In some embodiments, the page module  102  can be implemented, in part or in whole, as software, hardware, or any combination thereof. In general, a module as discussed herein can be associated with software, hardware, or any combination thereof. In some implementations, one or more functions, tasks, and/or operations of modules can be carried out or performed by software routines, software processes, hardware, and/or any combination thereof. In some cases, the page module  102  can be implemented, in part or in whole, as software running on one or more computing devices or systems, such as on a user or client computing device. In one example, the page module  102  or at least a portion thereof can be implemented as or within an application (e.g., app), a program, or an applet, etc., running on a user computing device or a client computing system, such as the user device  610  of  FIG. 6 . In another example, the page module  102  or at least a portion thereof can be implemented using one or more computing devices or systems that include one or more servers, such as network servers or cloud servers. In some instances, the page module  102  can, in part or in whole, be implemented within or configured to operate in conjunction with a social networking system (or service), such as the social networking system  630  of  FIG. 6 . 
     The page module  102  can be configured to communicate and/or operate with the at least one data store  108 , as shown in the example system  100 . The at least one data store  108  can be configured to store and maintain various types of data including, for example, location data (e.g., check-in data) obtained from users of the social networking system. In general, users can choose whether or not to opt-in to utilize any of the features described herein, including whether or not to provide location data. The disclosed technology can also ensure that various privacy settings and preferences are maintained and can prevent private information from being divulged. In some implementations, the at least one data store  108  can store information associated with the social networking system (e.g., the social networking system  630  of  FIG. 6 ). The information associated with the social networking system can include data about users, social connections, social interactions, locations, geo-fenced areas, maps, places, events, pages, groups, posts, communications, content, feeds, account settings, privacy settings, a social graph, and various other types of data. In some implementations, the at least one data store  108  can store information associated with users, such as user identifiers, user information, profile information, user specified settings, content produced or posted by users, and various other types of user data. 
     In various embodiments, the geographic clustering module  104  is configured to generate geographic clusters. More details regarding the geographic clustering module  104  will be provided below with reference to  FIG. 2 . The page recommending module  106  can be configured to provide page recommendations to users. More details regarding the page recommending module  106  will be provided below with reference to  FIG. 3 . 
       FIG. 2  illustrates an example of a geographic clustering module  202  configured to generate geographic clusters, according to an embodiment of the present disclosure. In some embodiments, the geographic clustering module  104  of  FIG. 1  can be implemented as the geographic clustering module  202 . As shown in  FIG. 2 , the geographic clustering module  202  can include a data module  204 , a clustering module  206 , and a cluster processing module  208 . As mentioned, the geographic clustering module  202  can be configured to generate geographic clusters based, in part, on user location data. A geographic cluster can define some geographic boundary that corresponds to a geographic region such as a “neighborhood”, e.g., a social community in which residents tend to frequently interact and/or visit places. 
     In various embodiments, the data module  204  is configured to prepare data that will be used to generate the geographic clusters. This data can be determined using user location data that has been collected, or obtained, by the social networking system. The location data can reference geographic locations, or places, throughout the world at which users of the social networking system have visited and/or checked in. Rather than performing the clustering using location data from around the world, in some instances, the location data may be segmented, or divided, to facilitate the clustering process. In some embodiments, the data is divided using a fast clustering algorithm (e.g., k-means clustering) to divide the location data into geographic chunks. In general, each geographic chunk is larger than a city but still of a size on which clustering can be performed optimally. In some embodiments, the clustering process can be performed for each chunk, for example, by using the user location data that corresponds to the chunk as input. 
     In some embodiments, the data for generating geographic clusters is determined by identifying a set of top cities (e.g., 1024 cities) that have the most total number of user check-ins. In such embodiments, any city that is within a threshold distance (e.g., 45 km) of a top city is associated with the top city. This results in a set of clustered cities. For each clustered city, the users who are residents of the clustered city are identified. This results in a set of clustered users. Next, for each of the overlapping sets of clustered people, all of the places visited (or checked into) by the users are identified. A similarity matrix W that describes the respective similarities between these places is determined, as described below, and spectral clustering can be performed on this similarity matrix W to generate the geographic clusters. 
     In some embodiments, the data for generating geographic clusters is determined by identifying chunks that each correspond to a metropolitan area. In such embodiments, the clustering process can be performed on each metropolitan area using its corresponding user location data as input. In general, each metropolitan area can include, or encompass, one or more cities. By grouping cities into metropolitan areas, the risk choosing an incorrect neighborhood boundary can be reduced. In some embodiments, for any metropolitan area, the data module  204  disregards any location data that was provided by users that are not residents (e.g., tourists) of the metropolitan area (e.g., not residents of any cities included in the metropolitan area). In such embodiments, the data, therefore, includes location data of users that are determined to be residents of the metropolitan areas. By removing non-resident location data, noise, which may result in sub-optimal clustering, can be reduced. In one example, a user can be identified as a resident of a city and/or metropolitan area from information specified in the user&#39;s profile that is accessible through the social networking system. 
     A metropolitan area can be identified using various approaches. For example, in some embodiments, metropolitan areas can be identified by determining the respective number of times users visited each city (e.g., the number of user check-ins performed in each city) in a region (e.g., across the world, a continent, country, state, etc.) over some period of time (e.g., 30 days, 6 months, 1 year, etc.). For each city, a radius r (e.g., 45 km, 60 km, 80 km, etc.) is defined around the city for purposes of identifying a parent city. A parent city is any city that is geographically located within the radius r and which has the most number of user visits and/or check-ins. Any city that does not have a parent city located within its respective radius r is labeled as a hub of a metropolitan area. Any city that has a parent city within its respective radius r is labeled a child city which corresponds to the same metropolitan area as its parent city. In some embodiments, metropolitan areas can be identified by performing spectral clustering on the cities in a region (e.g., across the world, a continent, country, state, etc.). This approach can recursively sub-divide the world and can therefore provide a more realistic division between cities. 
     Once the data to be clustered has been separated into chunks using one of the approaches described above, the data module  204  can filter the data to remove any erroneous places. For example, in some instances, users may check-in to a place that identifies itself as being located in a geographic region (e.g., city) that is incorrect. For example, a user may check-in to a place that identifies itself in the social networking system as being located in San Francisco, Calif. but, in reality, is actually located in Oakland, Calif. In this example, check-ins corresponding to this place can be excluded from the data to be clustered. 
     In some embodiments, a clustering process is performed using a similarity matrix W that describes the respective similarities between places. As mentioned, the clustering can be performed separately for each chunk. In such instances, a separate similarity matrix W is determined for each chunk to be clustered. In general, the matrix W for a chunk includes a set of rows and columns where each row corresponds to a place that is located in a geographic region represented by the chunk and each column also corresponds to a place that is located in a geographic region represented by the chunk. In this example, a similarity between a first place and a second place can be determined, for example, using a cosine similarity. Thus, each entry in the matrix W can be determined as follows: 
         M   {i,j} =cos_sim( i,j ), 
     where i references a place i, where j references a place j, and where cos_sim(i, j) is the cosine similarity between place i and the place j. 
     In some embodiments, the cosine similarity between two places is determined as follows: 
     
       
         
           
             
               
                 ( 
                 
                   i 
                   · 
                   j 
                 
                 ) 
               
               
                 ( 
                 
                   
                      
                     i 
                      
                   
                   * 
                   
                      
                     j 
                      
                   
                 
                 ) 
               
             
             , 
           
         
       
     
     where (i·j) is the number of users that visited (or checked into) both place i and place j, where |i| is the square root of the number of people that visited (or checked into) place i, and where |j| is the square root of the number of people that visited (or checked into) place j. 
     The clustering module  206  can perform the clustering process for each of the chunks using a corresponding similarity matrix W determined for the chunk. In various embodiments, the clustering module  206  performs spectral clustering using the corresponding similarity matrix W. The spectral clustering can be performed by calculating the normalized Laplacian as follows: 
     
       
      
       L=D−W,  
      
     
     where D is the degree matrix, and where W is the similarity matrix. 
     The symmetric Laplacian can be calculated as follows: 
     
       
         
           
             
               L 
               norm 
             
             = 
             
               
                 D 
                 
                   - 
                   
                     1 
                     2 
                   
                 
               
                
               
                 
                   LD 
                   
                     - 
                     
                       1 
                       2 
                     
                   
                 
                 . 
               
             
           
         
       
     
     The random walk Laplacian can be calculated as follows: 
     
       
      
       L 
       norm 
       =D 
       −1 
       L.  
      
     
     Using the normalized Laplacian, the k smallest eigenvectors of L norm  can be identified and used as features in matrix U. The clustering module  206  can then perform k-means clustering on the matrix U to generate the geographic clusters for the chunk being processed. 
     In some embodiments, the cluster processing module  208  is configured to post-process the geographic clusters. The post-processing can involve, for example, addressing overlapping geographic clusters and/or geographic clusters that are overly large. In some embodiments, the cluster processing module  208  can detect overlapping clusters, for example, by comparing the respective convex hulls that correspond to the geographic clusters. In some embodiments, if two geographic clusters overlap, a determination is made whether one of the geographic clusters is a subset of the other. In this example, if one geographic cluster is a subset of the other, then the larger geographic cluster is removed. In some embodiments, when two geographic clusters overlap, but do not coincide (e.g., one cluster is not a subset of the other), the cluster processing module  208  measures the amount of overlap between the two geographic clusters. In some embodiments, the amount of overlap can be measured as follows: 
     
       
         
           
             
               overlap 
               = 
               
                 
                   area 
                    
                   
                     ( 
                     
                       A 
                        
                       
                           
                       
                       ⋂ 
                       B 
                     
                     ) 
                   
                 
                 
                   area 
                    
                   
                     ( 
                     
                       A 
                       ⋃ 
                       B 
                     
                     ) 
                   
                 
               
             
             , 
           
         
       
     
     where A corresponds to a first geographic cluster, and where B corresponds to a second geographic cluster. Using this approach, the overlap is 1 if A and B are the same and overlap completely and 0 if A and B do not overlap at all. In some embodiments, if the overlap between A and B is greater than a threshold (e.g., ⅔), then the clusters A and B are merged to form a cluster A′ by determining A∪B. If the overlap between A and B less than or equal to the threshold (e.g., ⅔), then clusters A and B are split. In some embodiments, the clusters are split along the boundary of either cluster A or cluster B (e.g., new clusters A′=A−B and B′=B−A′). The cluster boundary to use for the split can be determined by which cluster set has the proportion of size that is closest to a threshold amount (e.g., ½) of the total area. 
     In some embodiments, the cluster processing module  208  can improve coverage by assigning geographic areas to clusters. In such embodiments, geographic areas are assigned to clusters based on their close proximity to the clusters. For example, for a place P that is not located within the convex hull of any cluster, a determination is made whether P is close to a cluster, e.g., there exists a cluster C with a radius r such that the distance from C&#39;s boundary to P satisfies a threshold value as follows: 
       distance( P ,boundary( C ))&lt;√{square root over ( r )}.
 
     In some embodiments, if the distance is satisfies the threshold value, the cluster processing module  208  can compute the respective distance between P to each cluster and can assign P to a nearest cluster as follows: 
       cluster=arg min C distance( P ,boundary( C )). 
       FIG. 3  illustrates an example of a page recommending module  302  configured to recommend pages, according to an embodiment of the present disclosure. In some embodiments, the page recommending module  106  of  FIG. 1  can be implemented as the page recommending module  302 . As shown in  FIG. 3 , the page recommending module  302  can include a candidate generation module  304  and a recommender module  306 . 
     The candidate generation module  304  is configured to determine pages that can be recommended to users based on the geographic clusters. In some embodiments, the candidate generation module  304  can correlate user location data with geographic clusters to determine which regions (e.g., neighborhoods) a user frequents. Whether a user frequents a cluster can be determined in a number of ways including, for example, based on a threshold amount of time the user is located in a geographic region defined by the cluster or based on a threshold proportion of check-ins performed by the user while being located in a geographic region defined by the cluster. Using this information, the user can be recommended pages that are associated with the geographic clusters frequented by the user. For example, in some embodiments, pages can be associated with one or more geographic centroids. A centroid for a page can be computed based on a distribution of the respective locations of users that are connected with, or fans of, the page. Based on the variance of the distribution, the page may be classified in a local, regional, country, or global category. The centroid(s) determined for the page can be used to determine one or more radii that represent areas of influence for the page. In one example, a geographic region corresponding to a p25 radius that extends from a centroid of a page includes 25 percent of the users that are associated with the page. In another example, a geographic region corresponding to a p50 radius that extends from a centroid of the page includes 50 percent of the users that are associated with the page. Further, a geographic region corresponding to a p75 radius that extends from a centroid of the page includes 75 percent of the users that are associated with the page. In some embodiments, a page can be associated with a geographic cluster in which a centroid for the page is located. In some embodiments, the location of a page&#39;s centroid with respect to a geographic cluster needs to be near the center of the cluster (within some threshold measurement) before the page can be associated with the cluster. 
     In some embodiments, suggestions (e.g., advertisements and/or recommendations) can be assigned to geographic clusters and such suggestions can be targeted to users based on the geographic clusters frequented by the user. In some embodiments, for each cluster, the pages having at least a threshold number of likes by users that are residents of a geographic region defined by the cluster can be identified. Such pages can then be recommended to users that are located at a place (or check-in to a place) that is located in a geographic region defined by the cluster. 
     The recommender module  306  is configured to determine user locations and to provide content based on the locations. For example, in some embodiments, a user location can be determined based geolocation data provided by a mobile device of the user and/or based on a user check-in. The location and/or check-in can be correlated with a geographic cluster to provide content (e.g., page recommendations and/or advertisements) to the user, as described above. 
       FIG. 4  illustrates an example diagram  400  of a geographic region  402  that has been segmented into geographic clusters  404 , according to an embodiment of the present disclosure. As mentioned, each geographic cluster  404  can define some geographic boundary. The boundary can correspond to a respective neighborhood, e.g., a social community in which residents tend to frequently interact and/or visit places (e.g., geographic locations, points of interests such as restaurants, coffee shops, etc.). In some instances, the geographic boundary defined by a geographic cluster  404  can be visualized using a respective convex hull, as illustrated in the example  FIG. 4 . 
       FIG. 5  illustrates an example process  500  for generating recommendations, according to an embodiment of the present disclosure. It should be appreciated that there can be additional, fewer, or alternative steps performed in similar or alternative orders, or in parallel, within the scope of the various embodiments discussed herein unless otherwise stated. At block  502 , one or more geographic clusters that each correspond to a respective portion of a geographic region are determined. Each geographic cluster represents a neighborhood that includes a set of places which users residing in the neighborhood tend to frequently visit. At block  504 , a determination can be made that a user is located in a portion of the geographic region that corresponds to a first geographic cluster. At block  506 , at least one content item can be provided to be presented to the user, the content item being associated with the first geographic cluster. 
     It is contemplated that there can be many other uses, applications, and/or variations associated with the various embodiments of the present disclosure. For example, in some cases, user can choose whether or not to opt-in to utilize the disclosed technology. The disclosed technology can also ensure that various privacy settings and preferences are maintained and can prevent private information from being divulged. In another example, various embodiments of the present disclosure can learn, improve, and/or be refined over time. 
     Social Networking System—Example Implementation 
       FIG. 6  illustrates a network diagram of an example system  600  that can be utilized in various scenarios, in accordance with an embodiment of the present disclosure. The system  600  includes one or more user devices  610 , one or more external systems  620 , a social networking system (or service)  630 , and a network  650 . In an embodiment, the social networking service, provider, and/or system discussed in connection with the embodiments described above may be implemented as the social networking system  630 . For purposes of illustration, the embodiment of the system  600 , shown by  FIG. 6 , includes a single external system  620  and a single user device  610 . However, in other embodiments, the system  600  may include more user devices  610  and/or more external systems  620 . In certain embodiments, the social networking system  630  is operated by a social network provider, whereas the external systems  620  are separate from the social networking system  630  in that they may be operated by different entities. In various embodiments, however, the social networking system  630  and the external systems  620  operate in conjunction to provide social networking services to users (or members) of the social networking system  630 . In this sense, the social networking system  630  provides a platform or backbone, which other systems, such as external systems  620 , may use to provide social networking services and functionalities to users across the Internet. 
     The user device  610  comprises one or more computing devices (or systems) that can receive input from a user and transmit and receive data via the network  650 . In one embodiment, the user device  610  is a conventional computer system executing, for example, a Microsoft Windows compatible operating system (OS), Apple OS X, and/or a Linux distribution. In another embodiment, the user device  610  can be a computing device or a device having computer functionality, such as a smart-phone, a tablet, a personal digital assistant (PDA), a mobile telephone, a laptop computer, a wearable device (e.g., a pair of glasses, a watch, a bracelet, etc.), a camera, an appliance, etc. The user device  610  is configured to communicate via the network  650 . The user device  610  can execute an application, for example, a browser application that allows a user of the user device  610  to interact with the social networking system  630 . In another embodiment, the user device  610  interacts with the social networking system  630  through an application programming interface (API) provided by the native operating system of the user device  610 , such as iOS and ANDROID. The user device  610  is configured to communicate with the external system  620  and the social networking system  630  via the network  650 , which may comprise any combination of local area and/or wide area networks, using wired and/or wireless communication systems. 
     In one embodiment, the network  650  uses standard communications technologies and protocols. Thus, the network  650  can include links using technologies such as Ethernet, 802.11, worldwide interoperability for microwave access (WiMAX), 3G, 4G, CDMA, GSM, LTE, digital subscriber line (DSL), etc. Similarly, the networking protocols used on the network  650  can include multiprotocol label switching (MPLS), transmission control protocol/Internet protocol (TCP/IP), User Datagram Protocol (UDP), hypertext transport protocol (HTTP), simple mail transfer protocol (SMTP), file transfer protocol (FTP), and the like. The data exchanged over the network  650  can be represented using technologies and/or formats including hypertext markup language (HTML) and extensible markup language (XML). In addition, all or some links can be encrypted using conventional encryption technologies such as secure sockets layer (SSL), transport layer security (TLS), and Internet Protocol security (IPsec). 
     In one embodiment, the user device  610  may display content from the external system  620  and/or from the social networking system  630  by processing a markup language document  614  received from the external system  620  and from the social networking system  630  using a browser application  612 . The markup language document  614  identifies content and one or more instructions describing formatting or presentation of the content. By executing the instructions included in the markup language document  614 , the browser application  612  displays the identified content using the format or presentation described by the markup language document  614 . For example, the markup language document  614  includes instructions for generating and displaying a web page having multiple frames that include text and/or image data retrieved from the external system  620  and the social networking system  630 . In various embodiments, the markup language document  614  comprises a data file including extensible markup language (XML) data, extensible hypertext markup language (XHTML) data, or other markup language data. Additionally, the markup language document  614  may include JavaScript Object Notation (JSON) data, JSON with padding (JSONP), and JavaScript data to facilitate data-interchange between the external system  620  and the user device  610 . The browser application  612  on the user device  610  may use a JavaScript compiler to decode the markup language document  614 . 
     The markup language document  614  may also include, or link to, applications or application frameworks such as FLASH™ or Unity™ applications, the Silverlight™ application framework, etc. 
     In one embodiment, the user device  610  also includes one or more cookies  616  including data indicating whether a user of the user device  610  is logged into the social networking system  630 , which may enable modification of the data communicated from the social networking system  630  to the user device  610 . 
     The external system  620  includes one or more web servers that include one or more web pages  622   a ,  622   b , which are communicated to the user device  610  using the network  650 . The external system  620  is separate from the social networking system  630 . For example, the external system  620  is associated with a first domain, while the social networking system  630  is associated with a separate social networking domain. Web pages  622   a ,  622   b , included in the external system  620 , comprise markup language documents  614  identifying content and including instructions specifying formatting or presentation of the identified content. As discussed previously, it should be appreciated that there can be many variations or other possibilities. 
     The social networking system  630  includes one or more computing devices for a social network, including a plurality of users, and providing users of the social network with the ability to communicate and interact with other users of the social network. In some instances, the social network can be represented by a graph, i.e., a data structure including edges and nodes. Other data structures can also be used to represent the social network, including but not limited to databases, objects, classes, meta elements, files, or any other data structure. The social networking system  630  may be administered, managed, or controlled by an operator. The operator of the social networking system  630  may be a human being, an automated application, or a series of applications for managing content, regulating policies, and collecting usage metrics within the social networking system  630 . Any type of operator may be used. 
     Users may join the social networking system  630  and then add connections to any number of other users of the social networking system  630  to whom they desire to be connected. As used herein, the term “friend” refers to any other user of the social networking system  630  to whom a user has formed a connection, association, or relationship via the social networking system  630 . For example, in an embodiment, if users in the social networking system  630  are represented as nodes in the social graph, the term “friend” can refer to an edge formed between and directly connecting two user nodes. 
     Connections may be added explicitly by a user or may be automatically created by the social networking system  630  based on common characteristics of the users (e.g., users who are alumni of the same educational institution). For example, a first user specifically selects a particular other user to be a friend. Connections in the social networking system  630  are usually in both directions, but need not be, so the terms “user” and “friend” depend on the frame of reference. Connections between users of the social networking system  630  are usually bilateral (“two-way”), or “mutual,” but connections may also be unilateral, or “one-way.” For example, if Bob and Joe are both users of the social networking system  630  and connected to each other, Bob and Joe are each other&#39;s connections. If, on the other hand, Bob wishes to connect to Joe to view data communicated to the social networking system  630  by Joe, but Joe does not wish to form a mutual connection, a unilateral connection may be established. The connection between users may be a direct connection; however, some embodiments of the social networking system  630  allow the connection to be indirect via one or more levels of connections or degrees of separation. 
     In addition to establishing and maintaining connections between users and allowing interactions between users, the social networking system  630  provides users with the ability to take actions on various types of items supported by the social networking system  630 . These items may include groups or networks (i.e., social networks of people, entities, and concepts) to which users of the social networking system  630  may belong, events or calendar entries in which a user might be interested, computer-based applications that a user may use via the social networking system  630 , transactions that allow users to buy or sell items via services provided by or through the social networking system  630 , and interactions with advertisements that a user may perform on or off the social networking system  630 . These are just a few examples of the items upon which a user may act on the social networking system  630 , and many others are possible. A user may interact with anything that is capable of being represented in the social networking system  630  or in the external system  620 , separate from the social networking system  630 , or coupled to the social networking system  630  via the network  650 . 
     The social networking system  630  is also capable of linking a variety of entities. For example, the social networking system  630  enables users to interact with each other as well as external systems  620  or other entities through an API, a web service, or other communication channels. The social networking system  630  generates and maintains the “social graph” comprising a plurality of nodes interconnected by a plurality of edges. Each node in the social graph may represent an entity that can act on another node and/or that can be acted on by another node. The social graph may include various types of nodes. Examples of types of nodes include users, non-person entities, content items, web pages, groups, activities, messages, concepts, and any other things that can be represented by an object in the social networking system  630 . An edge between two nodes in the social graph may represent a particular kind of connection, or association, between the two nodes, which may result from node relationships or from an action that was performed by one of the nodes on the other node. In some cases, the edges between nodes can be weighted. The weight of an edge can represent an attribute associated with the edge, such as a strength of the connection or association between nodes. Different types of edges can be provided with different weights. For example, an edge created when one user “likes” another user may be given one weight, while an edge created when a user befriends another user may be given a different weight. 
     As an example, when a first user identifies a second user as a friend, an edge in the social graph is generated connecting a node representing the first user and a second node representing the second user. As various nodes relate or interact with each other, the social networking system  630  modifies edges connecting the various nodes to reflect the relationships and interactions. 
     The social networking system  630  also includes user-generated content, which enhances a user&#39;s interactions with the social networking system  630 . User-generated content may include anything a user can add, upload, send, or “post” to the social networking system  630 . For example, a user communicates posts to the social networking system  630  from a user device  610 . Posts may include data such as status updates or other textual data, location information, images such as photos, videos, links, music or other similar data and/or media. Content may also be added to the social networking system  630  by a third party. Content “items” are represented as objects in the social networking system  630 . In this way, users of the social networking system  630  are encouraged to communicate with each other by posting text and content items of various types of media through various communication channels. Such communication increases the interaction of users with each other and increases the frequency with which users interact with the social networking system  630 . 
     The social networking system  630  includes a web server  632 , an API request server  634 , a user profile store  636 , a connection store  638 , an action logger  640 , an activity log  642 , and an authorization server  644 . In an embodiment of the invention, the social networking system  630  may include additional, fewer, or different components for various applications. Other components, such as network interfaces, security mechanisms, load balancers, failover servers, management and network operations consoles, and the like are not shown so as to not obscure the details of the system. 
     The user profile store  636  maintains information about user accounts, including biographic, demographic, and other types of descriptive information, such as work experience, educational history, hobbies or preferences, location, and the like that has been declared by users or inferred by the social networking system  630 . This information is stored in the user profile store  636  such that each user is uniquely identified. The social networking system  630  also stores data describing one or more connections between different users in the connection store  638 . The connection information may indicate users who have similar or common work experience, group memberships, hobbies, or educational history. Additionally, the social networking system  630  includes user-defined connections between different users, allowing users to specify their relationships with other users. For example, user-defined connections allow users to generate relationships with other users that parallel the users&#39; real-life relationships, such as friends, co-workers, partners, and so forth. Users may select from predefined types of connections, or define their own connection types as needed. Connections with other nodes in the social networking system  630 , such as non-person entities, buckets, cluster centers, images, interests, pages, external systems, concepts, and the like are also stored in the connection store  638 . 
     The social networking system  630  maintains data about objects with which a user may interact. To maintain this data, the user profile store  636  and the connection store  638  store instances of the corresponding type of objects maintained by the social networking system  630 . Each object type has information fields that are suitable for storing information appropriate to the type of object. For example, the user profile store  636  contains data structures with fields suitable for describing a user&#39;s account and information related to a user&#39;s account. When a new object of a particular type is created, the social networking system  630  initializes a new data structure of the corresponding type, assigns a unique object identifier to it, and begins to add data to the object as needed. This might occur, for example, when a user becomes a user of the social networking system  630 , the social networking system  630  generates a new instance of a user profile in the user profile store  636 , assigns a unique identifier to the user account, and begins to populate the fields of the user account with information provided by the user. 
     The connection store  638  includes data structures suitable for describing a user&#39;s connections to other users, connections to external systems  620  or connections to other entities. The connection store  638  may also associate a connection type with a user&#39;s connections, which may be used in conjunction with the user&#39;s privacy setting to regulate access to information about the user. In an embodiment of the invention, the user profile store  636  and the connection store  638  may be implemented as a federated database. 
     Data stored in the connection store  638 , the user profile store  636 , and the activity log  642  enables the social networking system  630  to generate the social graph that uses nodes to identify various objects and edges connecting nodes to identify relationships between different objects. For example, if a first user establishes a connection with a second user in the social networking system  630 , user accounts of the first user and the second user from the user profile store  636  may act as nodes in the social graph. The connection between the first user and the second user stored by the connection store  638  is an edge between the nodes associated with the first user and the second user. Continuing this example, the second user may then send the first user a message within the social networking system  630 . The action of sending the message, which may be stored, is another edge between the two nodes in the social graph representing the first user and the second user. Additionally, the message itself may be identified and included in the social graph as another node connected to the nodes representing the first user and the second user. 
     In another example, a first user may tag a second user in an image that is maintained by the social networking system  630  (or, alternatively, in an image maintained by another system outside of the social networking system  630 ). The image may itself be represented as a node in the social networking system  630 . This tagging action may create edges between the first user and the second user as well as create an edge between each of the users and the image, which is also a node in the social graph. In yet another example, if a user confirms attending an event, the user and the event are nodes obtained from the user profile store  636 , where the attendance of the event is an edge between the nodes that may be retrieved from the activity log  642 . By generating and maintaining the social graph, the social networking system  630  includes data describing many different types of objects and the interactions and connections among those objects, providing a rich source of socially relevant information. 
     The web server  632  links the social networking system  630  to one or more user devices  610  and/or one or more external systems  620  via the network  650 . The web server  632  serves web pages, as well as other web-related content, such as Java, JavaScript, Flash, XML, and so forth. The web server  632  may include a mail server or other messaging functionality for receiving and routing messages between the social networking system  630  and one or more user devices  610 . The messages can be instant messages, queued messages (e.g., email), text and SMS messages, or any other suitable messaging format. 
     The API request server  634  allows one or more external systems  620  and user devices  610  to call access information from the social networking system  630  by calling one or more API functions. The API request server  634  may also allow external systems  620  to send information to the social networking system  630  by calling APIs. The external system  620 , in one embodiment, sends an API request to the social networking system  630  via the network  650 , and the API request server  634  receives the API request. The API request server  634  processes the request by calling an API associated with the API request to generate an appropriate response, which the API request server  634  communicates to the external system  620  via the network  650 . For example, responsive to an API request, the API request server  634  collects data associated with a user, such as the user&#39;s connections that have logged into the external system  620 , and communicates the collected data to the external system  620 . In another embodiment, the user device  610  communicates with the social networking system  630  via APIs in the same manner as external systems  620 . 
     The action logger  640  is capable of receiving communications from the web server  632  about user actions on and/or off the social networking system  630 . The action logger  640  populates the activity log  642  with information about user actions, enabling the social networking system  630  to discover various actions taken by its users within the social networking system  630  and outside of the social networking system  630 . Any action that a particular user takes with respect to another node on the social networking system  630  may be associated with each user&#39;s account, through information maintained in the activity log  642  or in a similar database or other data repository. Examples of actions taken by a user within the social networking system  630  that are identified and stored may include, for example, adding a connection to another user, sending a message to another user, reading a message from another user, viewing content associated with another user, attending an event posted by another user, posting an image, attempting to post an image, or other actions interacting with another user or another object. When a user takes an action within the social networking system  630 , the action is recorded in the activity log  642 . In one embodiment, the social networking system  630  maintains the activity log  642  as a database of entries. When an action is taken within the social networking system  630 , an entry for the action is added to the activity log  642 . The activity log  642  may be referred to as an action log. 
     Additionally, user actions may be associated with concepts and actions that occur within an entity outside of the social networking system  630 , such as an external system  620  that is separate from the social networking system  630 . For example, the action logger  640  may receive data describing a user&#39;s interaction with an external system  620  from the web server  632 . In this example, the external system  620  reports a user&#39;s interaction according to structured actions and objects in the social graph. 
     Other examples of actions where a user interacts with an external system  620  include a user expressing an interest in an external system  620  or another entity, a user posting a comment to the social networking system  630  that discusses an external system  620  or a web page  622   a  within the external system  620 , a user posting to the social networking system  630  a Uniform Resource Locator (URL) or other identifier associated with an external system  620 , a user attending an event associated with an external system  620 , or any other action by a user that is related to an external system  620 . Thus, the activity log  642  may include actions describing interactions between a user of the social networking system  630  and an external system  620  that is separate from the social networking system  630 . 
     The authorization server  644  enforces one or more privacy settings of the users of the social networking system  630 . A privacy setting of a user determines how particular information associated with a user can be shared. The privacy setting comprises the specification of particular information associated with a user and the specification of the entity or entities with whom the information can be shared. Examples of entities with which information can be shared may include other users, applications, external systems  620 , or any entity that can potentially access the information. The information that can be shared by a user comprises user account information, such as profile photos, phone numbers associated with the user, user&#39;s connections, actions taken by the user such as adding a connection, changing user profile information, and the like. 
     The privacy setting specification may be provided at different levels of granularity. For example, the privacy setting may identify specific information to be shared with other users; the privacy setting identifies a work phone number or a specific set of related information, such as, personal information including profile photo, home phone number, and status. Alternatively, the privacy setting may apply to all the information associated with the user. The specification of the set of entities that can access particular information can also be specified at various levels of granularity. Various sets of entities with which information can be shared may include, for example, all friends of the user, all friends of friends, all applications, or all external systems  620 . One embodiment allows the specification of the set of entities to comprise an enumeration of entities. For example, the user may provide a list of external systems  620  that are allowed to access certain information. Another embodiment allows the specification to comprise a set of entities along with exceptions that are not allowed to access the information. For example, a user may allow all external systems  620  to access the user&#39;s work information, but specify a list of external systems  620  that are not allowed to access the work information. Certain embodiments call the list of exceptions that are not allowed to access certain information a “block list”. External systems  620  belonging to a block list specified by a user are blocked from accessing the information specified in the privacy setting. Various combinations of granularity of specification of information, and granularity of specification of entities, with which information is shared are possible. For example, all personal information may be shared with friends whereas all work information may be shared with friends of friends. 
     The authorization server  644  contains logic to determine if certain information associated with a user can be accessed by a user&#39;s friends, external systems  620 , and/or other applications and entities. The external system  620  may need authorization from the authorization server  644  to access the user&#39;s more private and sensitive information, such as the user&#39;s work phone number. Based on the user&#39;s privacy settings, the authorization server  644  determines if another user, the external system  620 , an application, or another entity is allowed to access information associated with the user, including information about actions taken by the user. 
     In some embodiments, the social networking system  630  can include an page module  646 . The page module  646  can, for example, be implemented as the page module  102  of  FIG. 1 . As discussed previously, it should be appreciated that there can be many variations or other possibilities. 
     Hardware Implementation 
     The foregoing processes and features can be implemented by a wide variety of machine and computer system architectures and in a wide variety of network and computing environments.  FIG. 7  illustrates an example of a computer system  700  that may be used to implement one or more of the embodiments described herein in accordance with an embodiment of the invention. The computer system  700  includes sets of instructions for causing the computer system  700  to perform the processes and features discussed herein. The computer system  700  may be connected (e.g., networked) to other machines. In a networked deployment, the computer system  700  may operate in the capacity of a server machine or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. In an embodiment of the invention, the computer system  700  may be the social networking system  630 , the user device  610 , and the external system  720 , or a component thereof. In an embodiment of the invention, the computer system  700  may be one server among many that constitutes all or part of the social networking system  630 . 
     The computer system  700  includes a processor  702 , a cache  704 , and one or more executable modules and drivers, stored on a computer-readable medium, directed to the processes and features described herein. Additionally, the computer system  700  includes a high performance input/output (I/O) bus  706  and a standard I/O bus  708 . A host bridge  710  couples processor  702  to high performance I/O bus  706 , whereas I/O bus bridge  712  couples the two buses  706  and  708  to each other. A system memory  714  and one or more network interfaces  716  couple to high performance I/O bus  706 . The computer system  700  may further include video memory and a display device coupled to the video memory (not shown). Mass storage  718  and I/O ports  720  couple to the standard I/O bus  708 . The computer system  700  may optionally include a keyboard and pointing device, a display device, or other input/output devices (not shown) coupled to the standard I/O bus  708 . Collectively, these elements are intended to represent a broad category of computer hardware systems, including but not limited to computer systems based on the x86-compatible processors manufactured by Intel Corporation of Santa Clara, Calif., and the x86-compatible processors manufactured by Advanced Micro Devices (AMD), Inc., of Sunnyvale, Calif., as well as any other suitable processor. 
     An operating system manages and controls the operation of the computer system  700 , including the input and output of data to and from software applications (not shown). The operating system provides an interface between the software applications being executed on the system and the hardware components of the system. Any suitable operating system may be used, such as the LINUX Operating System, the Apple Macintosh Operating System, available from Apple Computer Inc. of Cupertino, Calif., UNIX operating systems, Microsoft® Windows® operating systems, BSD operating systems, and the like. Other implementations are possible. 
     The elements of the computer system  700  are described in greater detail below. In particular, the network interface  716  provides communication between the computer system  700  and any of a wide range of networks, such as an Ethernet (e.g., IEEE 802.3) network, a backplane, etc. The mass storage  718  provides permanent storage for the data and programming instructions to perform the above-described processes and features implemented by the respective computing systems identified above, whereas the system memory  714  (e.g., DRAM) provides temporary storage for the data and programming instructions when executed by the processor  702 . The I/O ports  720  may be one or more serial and/or parallel communication ports that provide communication between additional peripheral devices, which may be coupled to the computer system  700 . 
     The computer system  700  may include a variety of system architectures, and various components of the computer system  700  may be rearranged. For example, the cache  704  may be on-chip with processor  702 . Alternatively, the cache  704  and the processor  702  may be packed together as a “processor module”, with processor  702  being referred to as the “processor core”. Furthermore, certain embodiments of the invention may neither require nor include all of the above components. For example, peripheral devices coupled to the standard I/O bus  708  may couple to the high performance I/O bus  706 . In addition, in some embodiments, only a single bus may exist, with the components of the computer system  700  being coupled to the single bus. Moreover, the computer system  700  may include additional components, such as additional processors, storage devices, or memories. 
     In general, the processes and features described herein may be implemented as part of an operating system or a specific application, component, program, object, module, or series of instructions referred to as “programs”. For example, one or more programs may be used to execute specific processes described herein. The programs typically comprise one or more instructions in various memory and storage devices in the computer system  700  that, when read and executed by one or more processors, cause the computer system  700  to perform operations to execute the processes and features described herein. The processes and features described herein may be implemented in software, firmware, hardware (e.g., an application specific integrated circuit), or any combination thereof. 
     In one implementation, the processes and features described herein are implemented as a series of executable modules run by the computer system  700 , individually or collectively in a distributed computing environment. The foregoing modules may be realized by hardware, executable modules stored on a computer-readable medium (or machine-readable medium), or a combination of both. For example, the modules may comprise a plurality or series of instructions to be executed by a processor in a hardware system, such as the processor  702 . Initially, the series of instructions may be stored on a storage device, such as the mass storage  718 . However, the series of instructions can be stored on any suitable computer readable storage medium. Furthermore, the series of instructions need not be stored locally, and could be received from a remote storage device, such as a server on a network, via the network interface  716 . The instructions are copied from the storage device, such as the mass storage  718 , into the system memory  714  and then accessed and executed by the processor  702 . In various implementations, a module or modules can be executed by a processor or multiple processors in one or multiple locations, such as multiple servers in a parallel processing environment. 
     Examples of computer-readable media include, but are not limited to, recordable type media such as volatile and non-volatile memory devices; solid state memories; floppy and other removable disks; hard disk drives; magnetic media; optical disks (e.g., Compact Disk Read-Only Memory (CD ROMS), Digital Versatile Disks (DVDs)); other similar non-transitory (or transitory), tangible (or non-tangible) storage medium; or any type of medium suitable for storing, encoding, or carrying a series of instructions for execution by the computer system  700  to perform any one or more of the processes and features described herein. 
     For purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the description. It will be apparent, however, to one skilled in the art that embodiments of the disclosure can be practiced without these specific details. In some instances, modules, structures, processes, features, and devices are shown in block diagram form in order to avoid obscuring the description. In other instances, functional block diagrams and flow diagrams are shown to represent data and logic flows. The components of block diagrams and flow diagrams (e.g., modules, blocks, structures, devices, features, etc.) may be variously combined, separated, removed, reordered, and replaced in a manner other than as expressly described and depicted herein. 
     Reference in this specification to “one embodiment”, “an embodiment”, “other embodiments”, “one series of embodiments”, “some embodiments”, “various embodiments”, or the like means that a particular feature, design, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of, for example, the phrase “in one embodiment” or “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, whether or not there is express reference to an “embodiment” or the like, various features are described, which may be variously combined and included in some embodiments, but also variously omitted in other embodiments. Similarly, various features are described that may be preferences or requirements for some embodiments, but not other embodiments. 
     The language used herein has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.