The present study discusses the relevance of measures of lexical diversity (LD) to the assessment of learner corpora. It also argues that existing measures of LD, many of which have become specialized for use with language corpora, are fundamentally measures of lexical repetition, are based on an etic perspective of language, and lack construct…

The authors present a model of lexical proficiency based on lexical indices related to vocabulary size, depth of lexical knowledge, and accessibility to core lexical items. The lexical indices used in this study come from the computational tool Coh-Metrix and include word length scores, lexical diversity values, word frequency counts, hypernymy…

A reliable index of lexical diversity (LD) has remained stubbornly elusive for over 60 years. Meanwhile, researchers in fields as varied as "stylistics," "neuropathology," "language acquisition," and even "forensics" continue to use flawed LD indices--often ignorant that their results are questionable and in…

Compares accuracy of five formulae in terms of their ability to model the type-token curves of written texts produced by learners and native speakers. The most accurate models are then used to consider unresolved issues of past research on lexical diversity: the relationship between lexical diversity and age, second language instruction (L2), L2…