Secondary Outcomes (end points)
(1) Direct performance effect estimated using both exam-specific regressions and within-student fixed effects models to compare token and no-token conditions across midterms, controlling for midterm difficulty and student fixed effects.
(2) Learning effect estimated on final exam module-specific scores using regression models with module fixed effects, assessing whether prior token exposure for a module predicts higher performance on that module in the final.
(3) Additional analyses include treatment–covariate interactions (e.g., baseline GPA, diagnostic scores, demographic/background variables) to explore heterogeneous treatment effects.
(4) Models incorporate pre-specified covariates (academic records, demographic/background data, standardized test scores, and other IRB-approved sources) and apply multiple testing adjustments, clustered standard errors, and robustness checks.