A novel approach to improving the usability of contemporary pervasive ICT systems, through the provision of an accurate conceptual model, was developed. The approach was then investigated through a 'proof of concept' study to evaluate whether rt was viable and would improve the usability of a system. Much of this work is related to that published in Macefield (2005a, 2005b, 2007b). The approach considered is termed the Derivative Model approach because the conceptual model provided to the user is derived from the conceptual model used by the designers of the system, and as a result is an accurate explanation of the system's conceptual model. This approach offers users both an Interface View and a Structural View of the system. The Interface View is designed to engender better functional mental models in the user. The Structural View is designed to engender better structural mental models in the user.