Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: A method of posting ephemeral posts is disclosed. The method starts with receiving, from a user of a social network, a request to post an ephemeral post, the request including an ephemeral variable associated with a threshold event. The ephemeral post is posted on behalf of the user. Then an occurrence of the threshold event is monitored. When the threshold event has not occurred, the post is allowed to be accessible to at least one viewer other than the user. When the threshold event has occurred, the post is blocked from being accessible by the at least one view other than the user.

Abstract: An exercise feedback system receives exercise data such as images or video captured by client devices of users performing exercises. The exercise feedback system may access a machine learning model trained using image of a population of users. The images used for training may be labeled, for example, as having proper or improper musculoskeletal form. The exercise feedback system may determine a metrics describing the musculoskeletal form of a user by applying the trained machine learning model to images of the user as input features. The exercise feedback system may generate feedback for a certain exercise using the metrics based on output predictions of the model. The feedback can be provided to a client device of the user or a physical therapist for presentation.

Abstract: A social networking system generates a newsfeed for a user to view when accessing the social networking system. Candidate stories associated with users of the social networking system are selected and an expected value score for each candidate story is determined. An expected value score is based on the probability of a user performing various types of interactions with a candidate story and a numerical value for each type of interaction. The numerical value for a type of interaction represents a value to the social networking system of the type of interaction. Based on the expected value scores, the candidate stories are ranked and the ranking used to select candidate stories for the newsfeed.

Abstract: A method of posting ephemeral posts is disclosed. The method starts with receiving, from a user of a social network, a request to post an ephemeral post, the request including an ephemeral variable associated with a threshold event. The ephemeral post is posted on behalf of the user. Then an occurrence of the threshold event is monitored. When the threshold event has not occurred, the post is allowed to be accessible to at least one viewer other than the user. When the threshold event has occurred, the post is blocked from being accessible by the at least one view other than the user.

Abstract: A method of posting ephemeral posts is disclosed. The method starts with receiving, from a user of a social network, a request to post an ephemeral post, the request including an ephemeral variable associated with a threshold event. The ephemeral post is posted on behalf of the user. Then an occurrence of the threshold event is monitored. When the threshold event has not occurred, the post is allowed to be accessible to at least one viewer other than the user. When the threshold event has occurred, the post is blocked from being accessible by the at least one view other than the user.

Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: An exercise feedback system receives exercise data captured by client devices of users performing musculoskeletal exercises. The exercise feedback system may provide captured images to a client device of a physical trainer (PT) who remotely provides feedback on the users' exercise performances, for example, by labeling images as indicative of proper or improper musculoskeletal form. A PT may track multiple users using a central feed, which includes content displayed in an order based on ranking of users by a model. Additionally, the exercise feedback system may provide an augmented reality (AR) environment. For instance, an AR graphic indicating a target musculoskeletal form for an exercise is overlaid on a video feed displayed by a client device. Responsive to detecting that a user's form is aligned to the AR graphic, the exercise feedback system may notify the user and trigger the start of the exercise.

Abstract: A method of posting ephemeral posts is disclosed. The method starts with receiving, from a user of a social network, a request to post an ephemeral post, the request including an ephemeral variable associated with a threshold event. The ephemeral post is posted on behalf of the user. Then an occurrence of the threshold event is monitored. When the threshold event has not occurred, the post is allowed to be accessible to at least one viewer other than the user. When the threshold event has occurred, the post is blocked from being accessible by the at least one view other than the user.

Abstract: A social networking system user may associate a graphical element representing the user's emotional reaction with a content item presented by the social networking system. The user is presented with one or more graphical elements maintained by the social networking system and selects a graphical element for associating with the content item. If certain graphical elements are selected, the social networking system prompts the user for compensation or requests compensation from an entity associated with the selected graphical element. The selected graphical element is associated with the content item and a connection, or other information, between the user and the object identifying the selected graphical element is stored by the social networking system. The selected graphical element may be displayed with the content item to the user and to other users connected to the user.

Abstract: An exercise feedback system receives exercise data captured by client devices of users performing musculoskeletal exercises. The exercise feedback system may provide captured images to a client device of a physical trainer (PT) who remotely provides feedback on the users' exercise performances, for example, by labeling images as indicative of proper or improper musculoskeletal form. A PT may track multiple users using a central feed, which includes content displayed in an order based on ranking of users by a model. Additionally, the exercise feedback system may provide an augmented reality (AR) environment. For instance, an AR graphic indicating a target musculoskeletal form for an exercise is overlaid on a video feed displayed by a client device. Responsive to detecting that a user's form is aligned to the AR graphic, the exercise feedback system may notify the user and trigger the start of the exercise.

Abstract: A method of posting ephemeral posts is disclosed. The method starts with receiving, from a user of a social network, a request to post an ephemeral post, the request including an ephemeral variable associated with a threshold event. The ephemeral post is posted on behalf of the user. Then an occurrence of the threshold event is monitored. When the threshold event has not occurred, the post is allowed to be accessible to at least one viewer other than the user. When the threshold event has occurred, the post is blocked from being accessible by the at least one view other than the user.

Abstract: An exercise feedback system receives exercise data captured by client devices of users performing musculoskeletal exercises. The exercise feedback system may provide captured images to a client device of a physical trainer (PT) who remotely provides feedback on the users' exercise performances, for example, by labeling images as indicative of proper or improper musculoskeletal form. A PT may track multiple users using a central feed, which includes content displayed in an order based on ranking of users by a model. Additionally, the exercise feedback system may provide an augmented reality (AR) environment. For instance, an AR graphic indicating a target musculoskeletal form for an exercise is overlaid on a video feed displayed by a client device. Responsive to detecting that a user's form is aligned to the AR graphic, the exercise feedback system may notify the user and trigger the start of the exercise.

Abstract: An exercise feedback system receives exercise data such as images or video captured by client devices of users performing exercises. The exercise feedback system may access a machine learning model trained using image of a population of users. The images used for training may be labeled, for example, as having proper or improper musculoskeletal form. The exercise feedback system may determine a metrics describing the musculoskeletal form of a user by applying the trained machine learning model to images of the user as input features. The exercise feedback system may generate feedback for a certain exercise using the metrics based on output predictions of the model. The feedback can be provided to a client device of the user or a physical therapist for presentation.

Abstract: A social networking system detects spam in comments posted by users of the social networking system. A spam prevention module of the social networking system retrieves content signals associated with a posted comment and analyzes the content signals to determine whether the posted comment contains spam content. The spam prevention module augments the content signal analysis by analyzing social signals of the posted comment. Based on the content signal analysis and the social signal analysis, the spam prevention module determines whether the posted comment is spam and takes remedial actions on detected spam, including blocking the comment and educating the user who posted the comment.

Abstract: A method of posting ephemeral posts is disclosed. The method starts with receiving, from a user of a social network, a request to post an ephemeral post, the request including an ephemeral variable associated with a threshold event. The ephemeral post is posted on behalf of the user. Then an occurrence of the threshold event is monitored. When the threshold event has not occurred, the post is allowed to be accessible to at least one viewer other than the user. When the threshold event has occurred, the post is blocked from being accessible by the at least one view other than the user.

Abstract: An exercise feedback system receives exercise data captured by client devices of users performing musculoskeletal exercises. The exercise feedback system may provide captured images to a client device of a physical trainer (PT) who remotely provides feedback on the users' exercise performances, for example, by labeling images as indicative of proper or improper musculoskeletal form. A PT may track multiple users using a central feed, which includes content displayed in an order based on ranking of users by a model. Additionally, the exercise feedback system may provide an augmented reality (AR) environment. For instance, an AR graphic indicating a target musculoskeletal form for an exercise is overlaid on a video feed displayed by a client device. Responsive to detecting that a user's form is aligned to the AR graphic, the exercise feedback system may notify the user and trigger the start of the exercise.

Abstract: An exercise feedback system receives exercise data captured by client devices of users performing musculoskeletal exercises. The exercise feedback system may provide captured images to a client device of a physical trainer (PT) who remotely provides feedback on the users' exercise performances, for example, by labeling images as indicative of proper or improper musculoskeletal form. A PT may track multiple users using a central feed, which includes content displayed in an order based on ranking of users by a model. Additionally, the exercise feedback system may provide an augmented reality (AR) environment. For instance, an AR graphic indicating a target musculoskeletal form for an exercise is overlaid on a video feed displayed by a client device. Responsive to detecting that a user's form is aligned to the AR graphic, the exercise feedback system may notify the user and trigger the start of the exercise.

Abstract: An exercise feedback system receives exercise data captured by client devices of users performing musculoskeletal exercises. The exercise feedback system may provide captured images to a client device of a physical trainer (PT) who remotely provides feedback on the users' exercise performances, for example, by labeling images as indicative of proper or improper musculoskeletal form. A PT may track multiple users using a central feed, which includes content displayed in an order based on ranking of users by a model. Additionally, the exercise feedback system may provide an augmented reality (AR) environment. For instance, an AR graphic indicating a target musculoskeletal form for an exercise is overlaid on a video feed displayed by a client device. Responsive to detecting that a user's form is aligned to the AR graphic, the exercise feedback system may notify the user and trigger the start of the exercise.

Abstract: In one embodiment, a method includes receiving, from a client system of a first user, a text query comprising a character string of n characters, generating a plurality of suggested queries based on the text query, where each suggested query comprises the character string of the text query and one or more query tokens, and where at least one of the query tokens of each suggested query partially matches the character string of the text query, and sending, to the client system responsive to receiving the nth character of the text query, instructions for displaying one or more suggested queries to the first user, where at least one of the suggested queries is displayed with a preview of one or more search results matching the suggested query.