4 The three sub-corpora include native scholars' L1 English abstracts (NE), Korean scholars' L2 English abstracts of which articles were written in English (QE, meaning quasi-L2 English), and finally Korean scholars' L2 English abstracts of which articles were produced in L1 Korean (KE).
by the speculation that Korean scholars' Korean articles may have served as source texts, Korean scholars' L2 English abstracts have been separately categorized into two different groups to prevent such source-text effects, if any.