Abstract: Apparatuses and methods are disclosed for identifying with a single, small activity monitor a particular type of activity from among a plurality of different activities. The monitor may include a multi-axis accelerometer and microcontroller configured to combine and process accelerometer data so as to generate features representative of an activity. The features may be processed to identify a particular activity (e.g., running, biking, swimming) from among a plurality of different activities that may include activities not performed by a human subject. The activity monitor may be configured to further process the features to calculate various parameters characterizing the activity (e.g., duration of activity, total steps, distance traveled, intensity of activity, and calories burned). The monitor may identify a location on a subject where the monitor is worn, and provide a measure of the quality of the processed data or calculated parameters.