An event tracker detects instances of events of a user and an activity analyzer detects instances of activities of the user based at least in part on sensor data. The activity analyzer identifies candidate activities for each of the instances of the events and detects one or more patterns of user behavior of the user corresponding to a designated activity of the candidate activities from the instances of the events. The activity analyzer further predicts values of semantic characteristics of the designated activity from the one or more patterns of user behavior. Further, the activity analyzer identifies an instance of the designated activity as a practiced activity using the predicted values of the semantic characteristics and actual values of the semantic characteristics of the instance of the designated activity in an activity model that represents the designated activity. Personalized content is provided to the user based on the identified practiced activity.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A computer-implemented system comprising: one or more sensors configured to provide sensor data; an event tracker configured to detect instances of events of a user based at least in part on the sensor data; an activity analyzer configured to detect instances of activities of the user based at least in part on the sensor data; one or more processors; and one or more computer storage media storing computer-useable instructions that, when used by the one or more processors, cause the one or more processors to perform operations comprising: identifying, using the activity analyzer, candidate activities for each of the instances of the events; detecting one or more patterns of user behavior of the user corresponding to a designated activity of the candidate activities from the instances of the events; predicting values of semantic characteristics of the designated activity from the one or more patterns of user behavior; identifying, by the activity analyzer, an instance of the designated activity as a practiced activity using the predicted values of the semantic characteristics and actual values of the semantic characteristics of the instance of the designated activity in an activity model that represents the designated activity; and providing personalized content to a user device associated with the user based on the identified practiced activity. 2. The computer-implemented system of claim 1, wherein the identifying the instance of the designated activity as a practiced activity comprises increasing a level of confidence that the instance of the designated activity is a practiced activity based on detecting an instance of a complementary activity corresponding to the designated activity. 3. The computer-implemented system of claim 1, further comprising calculating a loyalty score of the user based on a variance in historical values of at least one of semantic characteristics, the identifying of the instance of the designated activity as the practiced activity being based on the loyalty score. 4. The computer-implemented system of claim 1, wherein the providing of the personalized content to the user device comprises calculating a loyalty score of the user based on a variance in historical values of at least one of semantic characteristics; selecting one of the historical values based on the loyalty score exceeding a threshold value; and selecting the personalized content based on the selected one of the historical values. 5. The computer-implemented system of claim 1, wherein the providing of the personalized content to the user device comprises calculating a loyalty score of the user based on a variance in historical values of at least one of semantic characteristics; selecting an aberrant value based on the loyalty score being below a threshold value; and selecting the personalized content based on the selected aberrant value. 6. The computer-implemented system of claim 1, wherein at least one of the semantic characteristics represents one or more participants of the instance of the designated activity. 7. The computer-implemented system of claim 1, wherein each candidate activity corresponds to a respective activity model, each activity model comprises a respective set of tracked features. 8. The computer-implemented system of claim 1, wherein each instance of the instances of the events correspond to an event model comprising a set of tracked features. 9. The computer-implemented system of claim 1, wherein the instance of the designated activity is a contemporary activity and the actual values of the semantic characteristics are real-time values. 10. A computer-implemented method comprising: determining real-time values of semantic characteristics of a user corresponding to a contemporary event from one or more sensors configured to provide sensor data; predicting, for each activity model of a plurality of activity models, values of the semantic characteristics of the activity model based on one or more patterns of user behavior extracted from historical instances of events; generating activity scores for the plurality of activity models based on a comparison between the predicted values of the semantic characteristics and the real-time values of the semantic characteristics, each activity score quantifying a level of confidence that one of the plurality of activity models is a practiced activity; selecting one or more practiced activities of the user from the plurality of activity models based on the activity scores; and providing personalized content to a user device associated with the user based on the at least one of the one or more selected practiced activities. 11. The computer-implemented method of claim 10, wherein the identifying the instance of the designated activity as a practiced activity comprises increasing a level of confidence that the instance of the designated activity is a practiced activity based on detecting an instance of a complementary activity corresponding to the designated activity. 12. The computer-implemented method of claim 10, wherein at least one of the plurality of activity models is a sub-activity model of a primary activity model of the plurality of activity models, the primary activity model comprising a set of tracked features and the sub-activity model comprising the set of tracked features and one or more additional track features. 13. The computer-implemented method of claim 10, wherein the activity score of at least one of the plurality of activity models is independent from user location. 14. The computer-implemented method of claim 10, wherein the selecting the one or more practiced activities of the user from the plurality of activity models comprises selecting two or more practiced activities. 15. The computer-implemented method of claim 10, wherein the one or more patterns of user behavior are formed by time stamps assigned to the historical instances of events. 16. The computer-implemented method of claim 10, further comprising identifying the contemporary event from the real-time values of the semantic characteristics; determining that the contemporary event corresponds to a visit of a venue by the user; identifying a local category corresponding to the venue based on the determining; and selecting the plurality of activity models from a larger set of activity models for the generating of the activity scores based on local category. 17. A computer-implemented method comprising: detecting instances of events of a user based at least in part on sensor data from one or more sensors; for each instance of the events: receiving an indication of a location associated with a user, the location determined based at least in part on the sensor data; mapping the location to one or more activity models, the one or more activity models each being candidate actives for the instance of the events; and calculating activity scores for each candidate activity of the candidate activities, each activity score quantifying a level of confidence that the instance of the events corresponds to the candidate activity; predicting values of semantic characteristics of a designated activity of the candidate activities from one or more patterns of user behavior extracted from the instances of the events based on the activity scores; identifying an instance of the designated activity as a practiced activity using the predicted values of the semantic characteristics and actual values of the semantic characteristics in an activity model that represents the designated activity; and providing personalized content to a user device associated with the user based on the identified practiced activity. 18. A computer-implemented method of claim 17, wherein the mapping the location to one or more activity models comprises: identifying a venue visited by the user based on the location; determining a local category assigned to the location; and selecting the one or more activity models from a set of activity models based on each of the one or more activity models corresponding to the local category, wherein each activity model in the set of activity models defines one or more local categories for the activity model. 19. A computer-implemented method of claim 17, wherein the instance of the designated activity is a multi-event activity corresponding to multiple-historical events. 20. A computer-implemented method of claim 17, wherein each instance of the events comprises a plurality of candidate activities.