Systems and methods are provided for constructing a classification architecture for a pattern recognition classifier that determines an associated occupant class of an occupant within a vehicle. A plurality of occupant classes are defined, with at least one of the occupant classes having an associated set of subclasses (202). A hierarchy of subclass partitions is determined based on a degree of similarity between subclasses associated with a given occupant class (210). Each successive partition in the hierarchy is an immediate partition of the preceding partition. The following is then performed iteratively until a termination event occurs. A subclass partition is selected according to the determined hierarchy (216/230). The fitness of a classifier model having an architecture derived from the selected subclass partition is evaluated (220). A class separation associated with the selected subclass partition is retained when the evaluated fitness is better than that of the preceding subclass partition in the hierarchy (224).