This document summarizes a doctoral research proposal on evaluating the quality of modeling languages used together in model-driven engineering (MDE) environments. The research aims to address problems with selecting languages for MDE projects and evaluating their suitability as a set. The researcher has conducted an initial review of quality frameworks and developed a first version of a conceptual framework. The proposed outcome is an "ontological quality evaluation framework" to assess language sets for their ability to be incorporated and adopted in MDE based on core concepts from information systems development and MDE.