Phraseological sophistication as a multidimensional construct

Abstract Since Paquot (2019) , several unresolved issues have persisted regarding the operationalization of phraseological sophistication in L2 complexity research. One of the most crucial concerns relates to the extent to which the commonly used measures of phraseological sophistication (MI scores) fully represent the intended construct. In this study, we draw upon insights from L2 phraseological research to reexamine the conceptualization and operationalization of phraseological sophistication. We conduct new analyses on the learner corpus used in Paquot (2019) , using alternative operationalizations of phraseological sophistication that represent different dimensions of sophistication (based on the register specificity of word combinations and their frequency). Results show that measures representing the dimensions of association (MI scores) and register specificity (ratios of academic collocations) correlate with each other. Frequency-based measures, however, pattern very differently, which we attribute to some issues in the way we operationalized frequency of co-occurrence.