Our research draws on diverse domains: Psychology, service management, human factors, ergonomics, universal design and new public governance to develop a scale for citizen experience measurement. We use the byzantine environment of taxation administration to test and further improve our evaluation model. Our model known as Experience Effectiveness (XE), challenges traditional thinking of service quality as a function of client satisfaction or loyalty. XE uses a multi-participant perspective and is defined in humanist terms of usability, service co-production and the successful completion of the service objective. This paper demonstrates that the strategic use of design in public sector administration can be used to improve citizens' lives. Through evaluating the experiences citizens have interacting with the public sector, governments can prioritise issues, reduce bureaucratic complexity and design better services. Improved public administration will ensure more effective use of revenue and higher levels of compliance with the law through seamless, transparent engagement and higher levels of citizen satisfaction. Initial results from the first of two studies are presented to show the practical application of the XE tool. In the taxation environment, we use the process of starting a small business in Australia as a test case. Both the XE measurement model and the associated citizen-client design are evaluated. The results have significance for all areas that require an objective measure of the impact of design on clients. Experience Effectiveness will also provide objective measures for project governance and performance evaluation. The research demonstrates how successful design outcomes can be a pragmatic alternative to enforcement as the principal approach to deterrence as compliance management.