2. The system of claim 1 , wherein each of the forward classification stages is configured to classify the input data instances based on a respective set of first and second thresholds associated with the forward classification stage.
2. The system of claim 1 , wherein each of the forward classification stages is configured to classify the input data instances based on a respective set of first and second thresholds associated with the forward classification stage. 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.