Initial self-assessment calibration and post-baseline L2 speech comprehensibility trajectories: A secondary longitudinal analysis with explanatory learner reflections

This secondary longitudinal study examined whether early calibration between self-assessed and externally rated comprehensibility was associated with subsequent L2 speech comprehensibility growth across one semester. Using de-identified classroom data from 160 Jordanian EFL learners (558 learner-wave observations; 3348 ratings), the study combined mixed-effects modeling and brief post-task reflections. In the primary baseline-adjusted model, Waves 2–4 outcomes were estimated while conditioning on Wave 1 externally rated comprehensibility. More accurate initial calibration was associated with steeper later improvement, whereas baseline overconfidence was associated with flatter post-baseline trajectories. The focal interaction remained across robustness checks using the inherited full panel, raw listener means, complete-case data, categorical time, and rating-level modeling. Moderator evidence was weaker: English use supported growth generally, anxiety attenuated under the stricter specification, and pronunciation beliefs did not robustly moderate the association. Reflections suggested that accurate self-assessors drew on broader listener-oriented criteria, whereas overconfident learners more often treated task completion or felt fluency as evidence that they were easy to understand. The findings support a bounded longitudinal association between calibration and later comprehensibility trajectories.