Acquisition of a problem-solving skill: Levels of organization and use of working memory.
Richard A. Carlson, Boo Hock Khoo, Robin G. Yaure, Walter Schneider · Journal of Experimental Psychology General · 1990
The authors examined the acquisition of a problem-solving skill at three levels of organization (strategy, subgoal, and operator) and investigated changes in temporary storage, manipulation of information, and coordination of multiple representations.