 The egg-cracking case raises the problem of how to evaluate moderately large formalizations of common sense problems. Morgenstern and Shanahan express this issue explicitly.  Morgenstern suggests that the important criteria are (1) Epistemological adequacy (correspondence to intuitive reasoning, as experienced by people who engage in it), (2) Faithfulness to the real world, (3) Reusability, and (4) Elaboration tolerance.  It isn’t clear whether the first two of these criteria are too subjective to be useful.  To these, Shanahan adds (5) Usability, which probably is presupposed by Morgenstern’s third criterion. 