14. A mobile device, comprising: a plurality of sensors and a plurality of sensor groups, wherein each of the sensor groups is assigned at least one of the sensors, and wherein the sensor groups are arranged according to a hierarchy; and a plurality of classifiers, wherein each classifier is assigned to a sensor group, and wherein each classifier is configured to evaluate one or more contexts of the mobile device based on signals from one or more sensors assigned to the same sensor group as the classifier; wherein the mobile device is configured to: evaluate a first context of the mobile device by activating classification using at least two of the classifiers in sequence according to the hierarchy; and adapt a configuration of a classifier assigned to a lower level sensor group in the hierarchy based, at least in part, on a result of a classification by a classifier assigned to a higher level sensor group in the hierarchy.
14. A mobile device, comprising: a plurality of sensors and a plurality of sensor groups, wherein each of the sensor groups is assigned at least one of the sensors, and wherein the sensor groups are arranged according to a hierarchy; and a plurality of classifiers, wherein each classifier is assigned to a sensor group, and wherein each classifier is configured to evaluate one or more contexts of the mobile device based on signals from one or more sensors assigned to the same sensor group as the classifier; wherein the mobile device is configured to: evaluate a first context of the mobile device by activating classification using at least two of the classifiers in sequence according to the hierarchy; and adapt a configuration of a classifier assigned to a lower level sensor group in the hierarchy based, at least in part, on a result of a classification by a classifier assigned to a higher level sensor group in the hierarchy. 17. The mobile device of claim 14 , wherein activating classification using at least two of the classifiers in sequence comprises activating a classification by the classifier assigned to the higher level sensor group when a confidence level of a classification by the classifier assigned to the lower level sensor group is below a threshold.