Emotional and motivational outcomes of lab work in the secondary intermediate track: The contribution of a science center outreach lab

subsample of the 68-class cluster-randomised trial; secondary intermediate-track (Realschule) classes

German secondary intermediate-track ninth graders (age ~15); chemistry of starch unit.

Third report from the same cluster-randomised trial as Itzek-Greulich et al. 2015/2017, restricted to the intermediate school track and focused entirely on affective outcomes: emotions, intrinsic motivation, perceived competence, boredom. All outcomes are student self-report questionnaires administered in situ and pre/post — no behavioural or attainment proxy for motivation (e.g. later science subject choice) is measured, which is the outcome that would actually matter for the 'labs recruit future scientists' argument. Same structural limitation: all treatment arms include lab work.

This is the paper that tests the MOTIVATION function of lab work — the function that most plausibly explains why practical science survived, and therefore the function any overturning verdict has to attack. Within a randomised trial, lab work (especially in the novel out-of-school setting) reliably raised situational interest, joy and perceived competence and lowered boredom in intermediate-track students. But the effects concentrate on state/situational affect rather than durable trait motivation towards science, and the study measures no downstream behaviour (subject uptake, option choice, later attainment). So the motivational case for labs is evidenced only at the level of 'students enjoy the lesson more' — which is real, randomised, and much better evidenced than the learning case, but is also the cheapest possible version of the claim.

Low — class-level randomisation; but self-reported affect is subject to demand and novelty effects that randomisation does not remove.

Same trial as the two Itzek-Greulich et al. papers; a different outcome set, not an independent replication.