A self-determination theory-based group intervention for academic motivation and well-being: a quasi-experimental study with Turkish middle school students

Objective Academic motivation and well-being are central to adolescent development, yet intervention research in Turkish middle schools is scarce. This study examined outcomes of a Self-Determination Theory (SDT) group intervention on intrinsic motivation, extrinsic motivation, amotivation, and well-being.Method Thirty 7th-grade students (17 girls, 13 boys; aged 13) were assigned by drawing lots to experimental (eight sessions), placebo (six non-academic sessions), or wait-list control groups (n = 10 each). Motivation and subjective well-being were measured with scales developed for Turkish adolescents. Non-parametric tests were used.Results At post-test, the experimental group scored higher on well-being, intrinsic motivation, and extrinsic motivation (all p < .001, ε2 ≥ .79). Post-test amotivation did not differ between the experimental and comparison groups, but the experimental group showed the largest reduction in gain scores (p < .001, ε2 = .64). Only the experimental group showed significant pre-post gains on all variables (all p~exact~ ≤.008, r ≥ .84).Conclusions Participation was associated with higher motivation and well-being and with a larger decrease in amotivation. Given the quasi-experimental design, baseline differences, and small sample, these findings are preliminary. They extend SDT intervention research to a non-Western, exam-oriented context.