Investigating the Role of Formative and Summative Assessments in Shaping English as a Second Language Learner Motivation through the Lens of Self-Determination Theory

Assessments significantly influence learner motivation in English as a Second Language (ESL) education. However, Sri Lankan state universities continue to rely heavily on summative evaluations, potentially undermining learner engagement. This study investigates the comparative impact of formative and summative assessments on undergraduates’ motivation through Self-Determination Theory (SDT), identifying autonomy, competence, and relatedness as core psychological needs that shape second language (L2) motivation. Adopting a mixed-methods approach, the research was conducted at a prominent state Buddhist university in Sri Lanka, with 20 first-year undergraduates enrolled in the “Compulsory English” course, combining a 15-item Likert scale questionnaire with follow-up interviews. Quantitative data were analyzed using SPSS to evaluate motivational perceptions across SDT domains, while thematic analysis was applied to qualitative responses for deeper insights. Results revealed that formative assessments more effectively supported the theoretical constructs, enhancing intrinsic motivation. Participants described formative tasks as less anxiety-inducing, equitable, and aligned with real-life language use, whereas summative assessments were perceived as rigid and stress-inducing. Although summatives were recognized for benchmarking, they largely failed to meet SDT’s psychological needs. The study concludes that formative assessments foster a more motivating learning environment and recommends a formative-weighted assessment model that emphasizes learner choice, timely feedback, and collaborative learning.