Measuring lexical complexity in L2 spoken production: Evidence from the Trinity Lancaster Corpus

Raffaella Bottini

CASS, Lancaster University

The study validates lexical complexity measures for L2 spoken language using the 4.2-million-word Trinity Lancaster Corpus of L2 spoken English. Studies on learner language have shown that vocabulary knowledge is one of the best predictors of language use and overall proficiency (e.g. Milton, 2013). Different measures of vocabulary knowledge have been proposed in the field and lexical complexity plays a key role among them (e.g. Kim et al., 2018; Kyle & Crossley, 2015; Lu, 2012). However, little is known about different aspects of lexical complexity in L2 speech; also, there is no general agreement about which of the many existing complexity indices to use. This corpus-based study examines the reliability and validity of existing lexical measures - including indices which have not been validated before - and their relationship with learner characteristics (L1 and proficiency) and task-related features (topic familiarity). It introduces Lex Complexity Tool, a new tool which computes all the measures analysed and which includes a spoken wordlist from the Spoken BNC2014. The findings inform the choice of lexical indices tailored to research in second language acquisition and language testing, especially when L2 English speech is considered.

Kyle, K., & Crossley, S. A. (2015). Automatically assessing lexical sophistication: Indices, tools, findings, and application. TESOL Quarterly, 49(4), 757-786.

Lu, X. (2012). The relationship of lexical richness to the quality of ESL learners' oral narratives. The Modern Language Journal, 96(2), 190-208.

Milton, J. (2013). Measuring the contribution of vocabulary knowledge to proficiency in the four skills. In C. Bardel, C. Lindqvist, & B. Laufer (Eds.), L2 vocabulary acquisition, knowledge and use. New perspectives on assessment and corpus analysis (pp. 57-78). Eurosla.

Week 6 2020/2021

Thursday 12th November 2020
2:00-3:00pm

Online: join mailing list or contact organisers to receive link

This session is not going to be recorded