5. The system of claim 3 , wherein the sets of first and second thresholds are determined based on training data associated with labels corresponding to the rejected class, an unconditionally accepted class, and a conditionally accepted class.
3. The system of claim 2 , wherein each of the forward classification stages is configured to classify each of the input data instances based on a comparison of the respective likelihood score with the respective set of first and second thresholds associated with the forward classification stage.