Abstract
The self-system model of motivational development was used in this study to examine whether and how student motivation and self-assessment practices-as psychological and behavioural mechanisms, respectively-link need-supportive teaching to students' objective achievement scores in English language learning. We applied a multilevel mediation analysis on Rasch-calibrated data from 796 students (53% females; mean age = 14.12, SD = 1.51) nested within 30 classes (mean class size = 26.53) in a secondary school in the Philippines. We collected all predictor variables (i.e. need-supportive teaching, motivation, self-assessment practice) in time 1, while achievement scores were collected eight weeks later (time 2). Lower-level mediation results show that students' perceptions of involved teaching and structured teaching are associated with higher controlled motivation and autonomous motivation. Furthermore, only autonomous motivation was associated with higher achievement in time 2. Self-assessment practice significantly mediated the link between both controlled and autonomous motivation to achievement. These results held while controlling for age, gender, and socioeconomic status. Hence, involved teaching and structured teaching correlated with higher motivation and increased self-assessment practice, which, in turn, leads to higher achievement in English language learning. The findings highlight that motivation and self-assessment practices are psychological and behavioural pathways that can theoretically and empirically explain how need-supportive teaching practices impact student achievement in a specific subject. Implications and directions for future research are discussed.