Sound conceptual models are commonly considered as an important factor for successful information systems (IS) development. Due to inaccurate conceptual specifications, IS projects can be delayed or even fail. Thus, thorough evaluation of models is a major concern in IS research. Consequently, theoretical models are required which elucidate the conditions for the successful evaluability of conceptual models. However, IS literature only provides little insights about the prerequisites of effective evaluation. Systematic investigations on the evaluability of conceptual models are missing. Therefore, is paper aims at two research results. Firstly, based on a comprehensive literature review we propose a theoretical model of perceived evaluability. This theoretical model rests on the influence of domain knowledge and the perceived comprehensibility of conceptual models as its two main impact factors. Secondly, to prepare an empirical evaluation of the theoretical model, the development of measurement scales is described. The first steps of this process are exemplified based on an inquiry of modeling experts and implications for testing our hypotheses are provided