Concepts and transformational knowledge

The effect of exposure to principled change in concept formation was invest igated in four experiments. In Experiment 1, participants were trained on e ither patterns that transformed systematically or control patterns that wer e distorted randomly. Training on transformational patterns produced concep ts that were more resistant to false intrusions and decay. Experiment 2 sep arated the relative influences of transformational knowledge and pairwise s imilarity. Participants were able to identify the next pattern in a transfo rmational sequence even though the foils were closer to the training patter ns. Experiment 3 investigated whether participants use transformational inf ormation in a speeded categorization task. Participants were faster at clas sifying patterns that continued a transformational path than patterns that fell off the path, only if they had trained on the transformational pattern s in a systematic order. Experiment 4 used multidimensional scaling to expl ore the psychological structure of transformational knowledge following tra ining. Analyses revealed clear evidence of a transformational path with sys tematic training. Implications for theories of similarity and categorizatio n are discussed. (C) 1999 Academic Press.