This article contributes to the debate about the appropriate use of corpus data in language learning research. It focuses on frequencies of linguistic features in language use and their comparison across corpora. The majority of corpus-based second language acquisition studies employ a comparative design in which either one or more second language…

Morphological complexity (MC) is a relatively new construct in second language acquisition (SLA). After critically discussing existing approaches to calculating MC in first- and second-language acquisition research, this article presents a new operationalization of the construct, the Morphological Complexity Index (MCI). The MCI is applied in two…