There has been a heated debate between connectionist and symbolic models on the task of learning the past tense of English verbs. Claims are often made, but not often justified, that a new model has a superior generalization ability to the previous ones. In this paper, we first set up a proper criterion for making comparisons between models. We point out a crucial issue in comparison which has been largely ignored in the past. Then we present results on the generalization ability of the symbolic pattern associator, SPA. We challenge connectionist researchers to design connectionist models with similar or better generalization ability.
