"Ten groups of 16 Ss received a total of 56 30-second trials tracking through simulated aircraft control dynamics. The variable under consideration was the degree of interaction between two of the major components of this tracking system, the lateral and vertical dimensions of flight control…. It was concluded that simplification rather than fractionation of a whole task provides for the more efficient training schedule when the whole requires or permits simultaneous responses to the several parts." (PsycINFO Database Record (c) 2006 APA, all rights reserved)