Understanding master’s thesis writers in a Finnish EMI context: Writing conceptions, apprehension about grammar, self-efficacy for thesis writing and thesis grade

English as a Medium of Instruction (EMI) results in an increasing number of students writing their master's theses in English as a second language (L2). The thesis process is challenging for many students, and academic writing in L2 English could add to these challenges. However, in EMI contexts, little is known about students’ writing and language-related conceptions and their relationship with writing success. Hence, this study investigates variation within and interconnections between master's thesis writers’ (N = 283, both L1 and L2 writers) self-efficacy for thesis writing, writing conceptions, apprehension about grammar, and thesis grade in a multilingual EMI university context in Finland. Data analyses included various statistical methods such as t-tests, two-step clustering, and ANOVAs. The findings indicate a positive connection between adaptive writing conceptions, thesis grade, and self-efficacy for thesis writing. Three groups of writers were identified, reflecting different combinations of writing conceptions, with significant differences in thesis grade, self-efficacy for thesis writing and apprehension about grammar. No significant differences were found between L1 and L2 writers.