1. A method comprising: receiving sensor data extracted from one or more physical sensors; using the extracted sensor data and a context model to perform a first level context determination; examining, with a processor, at least one condition; if the examining indicated that the at least one condition was fulfilled, adapting the context model on the basis of the sensor data without performance of another level of context determination, otherwise providing adaptation data formed on the basis of the sensor data to a second level context determination and using a combination of the extracted sensor data and virtual sensor data from virtual sensors configured to measure non-physical parameters to perform the second level context determination; and in an instance that the at least one condition of the first level context determination and at least one condition of the second level context determination are fulfilled, adapting a same context model.