Background: Evidence so far shows that Waldorf students are characterized by average science achievement but at the same time high socioeconomic status and high science motivation. Moreover, Waldorf education is characterized by high emphasis on inquiry-based science education (IBSE). The present study investigates if the specific attitude-achievement constellation of Waldorf students in science may be explained by the high level of IBSE.

Methods: Propensity score matching was applied to control for Waldorf students' more advantageous social background using the Austrian PISA 2015 sample (N = 7007 15-year old students). After propensity score matching, 1107 matched controls were included alongside all 149 Waldorf students.

Results: The results show that Waldorf students report higher enjoyment in learning science and more interest in broad science topics than matched controls. On the other hand, they demonstrate lower science achievement. Mediation analyses show that, although Waldorf students' more positive attitudes towards science can be almost entirely attributed to their higher exposure to IBSE, their underperformance in science cannot.

Conclusions: These results indicate that attending a school type with a high level of IBSE (Waldorf) may have positive effects on attitudinal outcomes (enjoyment and interest in science) whereas it does not seem to have notable effects on science achievement. This indicates that IBSE could be applied in educational contexts aiming to increase students' scientific attitudes.