This paper introduces a quantitative approach to assessing the effectiveness of student–tutor crit interactions in fostering constructivist learner-centred education in design studios. Implementing the learner-centred education approach is highly encouraged in constructivist education. However, methodological gaps in the quantitative assessment of its implementation restrict comparative studies and implementation across different settings. Based on the design practices learned and taught in studio crits, a quantitative measure of learner-centred education is developed. This measure accounts for the student’s cognitive engagement in introducing new design issues and active practice in developing these issues towards a design solution. The analysis techniques combine the syntactic tracking of the first occurrence of design issues, a coding of their types and the transitions between them using the Function–Behaviour–Structure ontology. A case study is presented to demonstrate the application of this learner-centred education metric in a natural experiment involving student–tutor interactions in six design critiques throughout a single semester. Critiques alternated between two different educational media. Results indicate that this approach can determine differences in the interaction and across media. This demonstrates the potential of the approach for assessing the effectiveness of student–tutor interactions for implementing learner-centred education in studio-based education.