Objectives To conduct a formative evaluation of applying the VALIDATE approach in practice by (i) assessing how students appreciated the e-learning course, (ii) exploring how, for what purposes and with what outcomes the acquired VALIDATE competences subsequently were used in internships in different institutional contexts, and how this was shaped by these contexts, and (iii) what this shows on real-world use of VALIDATE. Methods Comparative discussion of experiences of applying the VALIDATE approach via a semistructured survey and oral feedback from e-course students; final reports on internships in health technology assessment (HTA) practice, followed by semistructured interviews with interns and supervisors to complement and interpret results. Results All students considered the VALIDATE approach an enlightening and important addition to current HTA knowledge, especially regarding understanding the relation between empirical analysis and normative inquiry, identifying policy relevant questions and using the method of reconstructing interpretive frames for scoping. The latter appeared intellectually challenging and requiring some prior HTA knowledge. The use the VALIDATE approach in practice shows that interns productively redefined the HTA problem, based on appreciation of different stakeholders definition of the issue; they experienced constraints from retrieving all relevant perspectives from existing literature as well as from institutional rules and routines. Conclusions Some challenges in applying the VALIDATE approach deserve attention for its future use: currently used research approaches often assume a problem as "given"; and the data needed on different perspectives is often not reported in scientific literature. Finally, data gathering on and evaluation of value dimensions was experienced as challenging.