Use of evaluations and the evaluation of their use

All evaluations have a cost but not necessarily a value. Their value does not depend on their cost but on their use, and this article discusses factors affecting the use of evaluations. These factors could be taken into account in order to increase and improve the use made of evaluations and, consequently, their value. Two key issues (lags and the attribution problem) for the evaluation of the use of evaluations are discussed and a `possibilist' approach to evaluation use is presented.