This presentation comprises a critical overview of complexity research as it relates to lexicogrammatical development and an empirical study that demonstrates that a range of indices related to lexicogrammatical complexity can explain a substantial amount of variance in L2 proficiency scores. Implications for language assessment and future research are highlighted.
Productive lexical proficiency has been an important, if relatively under-researched topic in applied linguistics for over 25 years (e.g., Crossley et al., 2011; Kyle & Crossley, 2015; Laufer, 1994; Laufer & Nation, 1995; Meara & Bell, 2001). Most of this research has focused on the reference corpus frequency of the words produced by language learners (e.g., Laufer & Nation, 1995; Meara & Bell, 2001) though recent research has also explored other word-level characteristics (e.g., Crossley et al., 2011; Eguchi & Kyle, 2020; Kyle & Crossley, 2015). It is well known, however, that proficient word use goes beyond the knowledge of single words (Nation, 2001; Römer, 2009; Sinclair, 1991). Accordingly, recent research has demonstrated meaningful relationships between the use of frequent and strongly associated word combinations and judgements of production quality (Bestgen & Granger, 2014; Eguchi & Kyle, 2020; Garner et al., 2019). Researchers have begun to find that more proficient second language users also tend to use more schematic constructions such as verbs and their argument structures (e.g., give + double object construction; Kyle, 2016; Kyle & Crossley, 2017) and word combinations in particular grammatical relationships (e.g., verb – direct object; Paquot, 2018) that are more strongly associated. While research has indicated the importance of each of these features (i.e., words, bigrams, and dependency relationships) in isolation very little research has examined the relative contributions of each of these features in explaining judgements of second language production quality (c.f., Kyle & Eguchi, 2021). Furthermore, no studies that I am aware of have examined the relationship between dependency bigrams and measures of speaking proficiency. This study addresses these issues by investigating the relationship between features of word, bigram, and dependency bigram use and holistic speaking proficiency scores in an oral proficiency interview assessment.
