An on-line calculator to compute phonotactic probability and neighborhood density based on child corpora of spoken American English

Abstract

An on-line calculator was developed (http://www.bncdnet.ku.edu/cml/info_ccc.vi) to compute phonotactic probability, the likelihood of occurrence of a sound sequence, and neighborhood density, the number of phonologically similar words, based on child corpora of American English (Kolson, 1960; Moe, Hopkins, & Rush, 1982) and compared to an adult calculator. Phonotactic probability and neighborhood density were computed for a set of 380 nouns (Fenson et al., 1993) using both the child and adult corpora. Child and adult raw values were significantly correlated. However, significant differences were detected. Specifically, child phonotactic probability was higher than adult phonotactic probability, especially for high probability words; and child neighborhood density was lower than adult neighborhood density, especially for high density words. These differences were reduced or eliminated when relative measures (i.e., z scores) were used. Suggestions are offered regarding which values to use in future research.