Density and complexity of oral production in interaction: The interactionist approach and an alternative

This study examined conversational interaction between second language (L2) learners and native speakers (NSs). While L2 interaction research has traditionally quantified interactional moves - the interactionist approach, the present study examined various surface linguistic indices (e.g., MLUs, number of verb and noun types, and TTRs) and compared learner-learner vs. learner-NS interaction. The results indicated that learners and NSs were comparable in terms of the amount of production but the NSs' speech contained more grammatical and lexical variability with a larger mean proportion of copula omissions. This foreigner talk was found to be correlated with learners' errors. When learners' output in the two conditions was compared, it was found that learners produced more verb (but not noun) types with larger MLUs and TTRs in the peer interaction context.