My doctoral dissertation research examines complexity and accuracy in multilingual learners’ speech and writing across multiple languages. In the article-based dissertation, I examine the production of the first (L1), second (L2), and third language (L3) by incorporating typologically different languages as the target languages in the study: L1 Finnish, L2 English, and L3 Swedish.

The dissertation research investigates both oral and written production of L1 Finnish, L2 English, and L3 Swedish from the perspective of complexity and accuracy among Finnish university and university of applied sciences students. The study focuses on grammatical and lexical measures of complexity and accuracy, and the relationship between these measures across different languages. The dissertation is conducted as a mixed-methods study, utilising both quantitative and qualitative research. The methodological objective of the dissertation is to operationalise and develop measures suitable for comparing typologically different (Finnish) and similar (Swedish and English) languages.

Overall, the doctoral dissertation provides important new knowledge about the complexity and accuracy of multilingual learners in Finnish (L1), English (L2), and Swedish (L3), and creates significant novel perspectives and connections to international complexity, accuracy, and fluency (CAF) research.