Quantifying the Development of Inflectional Diversity

This study introduces a new metric for assessing the inflectional diversity of morphologically analyzed language transcripts. The proposed metric is based on the intuitive notion of mean size of paradigm (MSP) and makes extensive use of random sampling procedures for normalization purposes. This approach is systematically evaluated on the basis of large sets of Dutch acquisition corpora, including both child speech and child-directed speech. It is shown to be an efficient way of controlling for sample size in the measurement of inflectional diversity, as well as a suitable method for assessing inflectional development in longitudinal data. MSP is compared with ID (inflectional diversity) introduced by Malvern, Richards, Chipere, and Durán (2004).