Frequency Effects in Morpheme Segmentation

The present study explores the effects of frequency in learning to parse novel morphological patterns. In two experiments, suffixes were divided into three classes: high, medium and low frequency, based on the proportion of stems in the input that each suffix attached to (high frequency = 12/12, medium frequency = 6/12, and low frequency = 2/12). In Experiment 1, learners were better at segmenting words containing high frequency suffixes compared to low frequency suffixes, even when the stems were novel. In Experiment 2, token frequency was controlled for across all three suffix frequency classes, but learners were still better at segmenting high frequency suffixes, even when words containing high frequency suffixes were less frequent. These results suggest that learners are sensitive to the frequency distributions of the morphemes in their language, supporting work suggesting that a Zipfian distribution may be ideal for language learning.