This study examined the effects of type of assessment criteria (performance-based vs. competency-based), the relevance of assessment criteria (relevant criteria vs. all criteria), and their interaction on secondary vocational education students' performance and assessment skills. Students on three programmes in the domain of nursing and care (N = 93) participated in the study. Results show that students who were given the relevant criteria made more accurate assessments of an expert model, performed better on a test and achieved higher instructional efficiency (defined as the relationship between performance and mental effort) compared to students who were given all criteria. Students who were given performance-based assessment criteria made more accurate assessments of an expert model and scored higher on task performance during practice compared to students who were given competency-based assessment criteria. They invested less mental effort in the assessments, resulting in higher instructional efficiency. An interaction effect for the concreteness of answers shows that the combination of performance-based and relevant criteria leads to superior analysis of worked examples compared to the other combinations of criteria.