Structuring Error and Experimental Variation as Distribution in the Fourth Grade

Humans appear to have an inborn propensity to classify and generalize, activities that are fundamental to our understanding of the world (Medin, 1989). Yet, however one describes objects and events, their variability is at least as important as their similarity. In Full House, Stephen Jay Gould neatly drove home this point with his choice of a chapter subhead: “Variability as Universal Reality” (1996, p. 38). Gould (1996) further noted that modeling natural systems often entails accounting for their variability.