Lexical Performance by Native and Non-Native Speakers on Language-Learning Tasks

This chapter tries to integrate the measurement of lexis within general task-based performance, to complement existing measures of complexity, accuracy, and fluency. It discusses the range of measures (lexical diversity and lexical sophistication especially) and then uses a database of task-based studies to provide a comparison of native and non-native speaker performance; the interrelationship of measures of lexical diversity and lexical sophistication; the impact of task variables on lexical performance; and finally the role of pre-task planning. Implications are discussed for pedagogy and the central role of the second language mental lexicon is outlined.