Propositional learning is a useful research heuristic but it is not a theoretical algorithm
Baker AG., Baetu I., Murphy RA.
Mitchell et al.'s claim, that their propositional theory is a single-process theory, is illusory because they relegate some learning to a secondary memory process. This renders the single-process theory untestable. The propositional account is not a process theory of learning, but rather, a heuristic that has led to interesting research. © 2009 Cambridge University Press.