Individual lexical breadth and its associated measures. A contribution to the calculation of individual lexical richness

Abstract

In this chapter, we present an original model for the measurement of “individual lexical breadth”. With this construct, we try to represent lexical richness based on a solid and non-intuitive foundation, leading to the understanding that a speaker’s lexical breadth is the quantitative reflection of his or her degree of lexical richness. Thus, lexical breadth is a statistically proven quantitative measure of lexical richness. The model presented here is based on both the size and specificity of the vocabulary produced by a speaker during a lexical test, i.e., on their available lexicon. A principal difference between our measure of individual lexical breadth and others relating to lexical richness is that our measure reflects a characteristic of the speakers and not of the written production they produce. We propose a number of indexes based on our model, notably, the Index of Lexical Decentralization (ILD) and the Index of Lexical Amplitude (ILA). Our intention is for these indexes to be used in addition to the four above-mentioned parameters (i.e., content density, lexical sophistication, lexical accuracy and lexical diversity) in the calculation of lexical richness