23. The non-transitory processor-readable medium of claim 21 , further comprising: determining a count of one or more participants participating in the activity at the location for the first place and the labeled semantic place.
21. A non-transitory processor-readable medium that includes a program that when executed by a processor performs a method comprising: recognizing an activity performed at a first place based on sensor data of an electronic device, wherein the first place comprises an unlabeled semantic place without an assigned semantic place label; determining a location for the first place by performing localization for the electronic device; determining an observed mapping between the activity and the location for the first place; determining a typical mapping between the activity and a second place, wherein the second place comprises a labeled semantic place with an assigned semantic place label; based on the observed mapping and the typical mapping, assigning the same sematic place label assigned to the labeled semantic place to the location for the first place; and updating a semantic place map to include the semantic place label assigned to the location for the first place.