The problem of saying which properties become associated when multiple properties are coinstantiated sometimes goes by the name the “Credit Assignment Problem” (see, e.g., Gallistel and  King 2009).[39] Some would argue that this problem is a symptom of a larger issue: trying to use extensional criteria to specify intentional content (see, e.g., Fodor 2003). Associationists need a criterion to specify which of the coextensive properties will in fact be learned, and which not.