ABSTRACT
This chapter proposes the challenge of accounting for the learnability of other, more esoteric, but key concepts. It refers to the sixteen concepts defined by the modal operators as modal concepts. These concepts are central to cognition. The chapter focuses on the prospect of using generalized invariance structure theory (GIST) for predicting goodness of pattern judgments. W. R. Garner proposed that judgments on goodness of spatial patterns may be predicted by their symmetries. In a seminal study, L. E. Bourne studied and observed the learning-difficulty ordering of categories that could be described by the Boolean connectives or operators. There are sixteen possible Boolean operators or functions, a well-known fact in Boolean algebra. One of the key research questions advanced by Bourne pertained to the ability of subjects to identify which rules characterized particular categorical stimuli. Admittedly, this approach was significantly different from recent methods of studying concept-learning difficulty in terms of classification behavior.
