Interlanguage talk: A computational analysis of non-native speakers' lexical production and exposure

This study investigates the production of and exposure to lexical features when non-native speakers (NNS) converse with each other (NNS-NNS) engaging in interlanguage talk, as compared to when they engage in naturalistic speech with a native speaker (NS). The authors focus on lexical features that are associated with breadth of lexical knowledge including lexical diversity and lexical frequency. Spoken corpora from three types of dyads (NS-NNS, NNS-NS, NNS-NNS) are analyzed using the computational tool, Coh-Metrix. The results indicate that NNSs produce language with significantly greater lexical diversity and higher word frequency (i.e., more common words) when speaking to another NNS than when speaking to a NS. Hence, there is greater breadth of lexical knowledge apparent within interlanguage dyads (i.e., NNS-NNS) than within NNS-NS dyads in the variety of words produced, but not the frequency of the words. There were no significant differences in NNS exposure to breadth of lexical knowledge features as a function of whether the speaker was a NS or NNS. Hence, NNSs were exposed to similar levels of lexically comprehensible input regardless of interlocutor. These findings have important implications for the developmental role of interlanguage talk in reference to lexical production and exposure.