Formative feedback is widely recommended, yet its effect on intrinsic motivation remains contested. This study follows twelve secondary schools across one academic year to ask a narrower question: which properties of feedback, delivered by which route, move motivation rather than merely attainment.
We treat feedback as a designed intervention rather than a teacher trait, which lets us separate the frequency of feedback from its specificity.
Nine hundred and forty students in twelve schools took part. Schools were recruited to span the national distribution of intake attainment.
Motivation was measured with a validated self-report scale administered at three points. Feedback episodes were coded from lesson recordings by two independent raters.
Specificity, not frequency, predicted change in intrinsic motivation. Students receiving fewer but more specific comments reported larger gains than students receiving frequent but generic praise.
The association held after adjusting for baseline attainment and school.
The result suggests that advice to "give more feedback" is at best incomplete. Where teacher time is fixed, the trade-off between quantity and specificity is the decision that matters.
De-identified response data and the coding scheme are available as supplementary material accompanying this article.