In pursuit of public accountability, the mechanisms for assessing research performance have become more complicated and burdensome. In the United Kingdom, the Research Assessment Exercise (RAE) evolved from an initially simple framework to something much more complex and onerous. As the RAE now gives way to the Research Excellence Framework (REF), ‘impact assessment’ is being added to the process. Impact comes in numerous forms, however, so its assessment is far from straightforward. While the Higher Education Funding Council for England is initially proposing a relatively simple methodology, the history of the RAE suggests that this approach will over time become ever more sophisticated. Yet if the ‘costs’ of an elaborate system for assessing ‘research excellence’ and its impact then exceed the benefits, the time may have come to re-examine whether a dual-support system still represents the optimum way of funding university research. Copyright , Beech Tree Publishing.