A failure to differentiate

The K. J. Rust and T. S. Kendler paper (1987, Developmental Review, 7, 326–362) makes two claims to publication: (1) it claims to show (and implicitly, to show for the first time) that a nonselective learning model such as Spence's can fit the basic phenomenon of independent subproblem learning, and (2) it claims two experimental tests of the nonselective theory versus the differentiation theory interpretations of independent subproblem learning. Neither claim is valid and both claims reflect a failure to differentiate the literature. Moreover, Kendler's basic assumption of a developmental difference in the nature of learning is questionable.