Metacognitive modelling competencies are an essential part of modelling competence. When working on a modelling problem in small groups, the metacognitive modelling competencies of an individual may be less important, but in particular those shared in the group are of major importance. In this paper, results of a pilot study are presented which clearly indicate that measuring metacognitive group competencies is challenging. Furthermore, it is shown that the measurement of metacognitive competencies of individuals is not sufficient to get insight in the students' metacognitive behavior.