On the relationship between learning sequence and rate of acquisition

Abstract

Many error-driven learning algorithms for constraint-based phonological grammars, including the Gradual Learning Algorithm for Optimality Theory and Harmonic Grammar, predict that more frequent input forms will be acquired earlier than less frequent input forms – a fact that has been commonly taken as a virtue of these models. These models also predict, however, that the rate of learning for more frequent input forms should be faster than the rate of learning for less frequent input forms. In other words, these models predict that sequence and rate of acquisition are related; structures acquired earlier in the course of learning will be acquired more rapidly, while those that are acquired relatively later will be acquired more slowly. This paper explicates these predictions and argues that they are not consistently supported by child language data. Evidence from six children’s acquisition of consonant clusters is presented, demonstrating that, contrary to the predictions of the learning models, learning sequence and rate of acquisition are largely disassociated.