1. A system for providing more than two levels of classification distinction of a user state, comprising: a first two-state classifier configured to receive data representative of a first general state of a user and, upon receipt thereof, to classify the first general state of the user as either a first state or a second state and supply a first classification output representative thereof; a second two-state classifier configured to receive data representative of a second general state of the user and, upon receipt thereof, to classify the second general state of the user as either a third state or a fourth state and supply a second classification output representative thereof; and a classifier fusion module coupled to receive the first classification output and the second classification output and configured, upon receipt thereof, to classify the user state as one of at least three different classification states.