Four experiments explored participants' understanding of the abstract principles governing computer simulations of complex adaptive systems. Experiments 1, 2, and 3 showed better transfer of abstract principles across simulations that were relatively dissimilar, and that this effect was due to participants who performed relatively poorly on the…

Two experiments assessed whether children's difficulty with word problems can be attributed to difficulty in comprehending abstract or ambiguous language. The subjects were 38 first-, 36 second-, and 36 third-graders. The resulting theory of arithmetic word problem solving may represent a theoretical problem-solving model. (TJH)