Developing usability studies to evaluate software is a task requiring a wide variety of skills. For software developers who are not used to taking a user-centred approach to development it is often easier and more convenient to dismiss the use of user evaluation as too time-consuming or too hard. This is even more likely to be the case for developers who take a formal approach to software development, which is generally not focused on interface or usability concerns. In this paper we present an early investigation into the use of formal models of user interface designs as the basis for designing software evaluation studies. We have undertaken a comparison study to find out whether a useful study can be derived in this way and whether or not further investigation into this is worthwhile, and we present the results here.