View Complete Reference

Zbrodoff, NJ (1995)

Why is 9+7 harder than 2+3 - Strength and Interference as Explanations of the Problem-Size Effect

Memory & Cognition 23(6), 689-700.

ISSN/ISBN: 0090-502X DOI: 10.3758/BF03200922

Abstract: In four experiments, the problem-size effect was investigated, using an alphabet-arithmetic task in which subjects verified such problems as A + 2 = C. Problem size was manipulated by varying the magnitude of the digit addend (e.g., A + 2, A + 3, and A + 4). The frequency and similarity of problems was also manipulated to determine the contribution of strength and interference, respectively. Experiment 1 manipulated frequency at low levels of practice and found that strength could account for the problem-size effect. Experiment 2 manipulated frequency at higher levels of practice, and found that strength alone could not account for the problem-size effect at asymptote. Experiment 3 manipulated frequency and similarity and found a substantial problem-size effect at asymptote, suggesting that both strength and interference contribute to the problem-size effect. Experiment 4 manipulated similarity, keeping frequency constant, and found no problem-size effect at asymptote, suggesting that interference alone is not responsible for the problem-size effect. The results are related to findings with number arithmetic.

@article{, title={Why is 9+ 7 harder than 2+ 3? Strength and interference as explanations of the problem-size effect}, author={Zbrodoff, N Jane}, journal={Memory \& Cognition}, volume={23}, number={6}, pages={689--700}, year={1995}, publisher={Springer}, ISSN={0090-502X}, DOI={10.3758/BF03200922}, }

Reference Type: Journal Article

Subject Area(s): Psychology