1. Pylyshyn, Z. W.The explanatory adequacy of cognitive process models. Paper presented at the M.I.T. workshop on Cognitive Representation, Massachusetts Institute of Technology, January 1978 (mimeo).
2. Pylyshyn, Z. W. The symbolic nature of mental representations. Paper presented at a symposium onObjectives and methodologies in artificial intelligence, Australian National University, Canberra, May 1974 (mimeo).
3. Shepard, R. N. Personal communication, 1978.
4. Pomerantz, J. Personal communication, 1978.