Increasingly, in the world of evaluation, `systems of evaluation' have been developed.this article outlines four criteria that help characterize such systems. One criterion is the existence of a distinctive epistemological perspective; another is that, in order to be labelled a system, evaluation activities are carried out by evaluators within organizational structures and institutions and not only (or largely) by `lonely' or sole-trader evaluators. Permanence is the third criterion and the fourth is that there is a focus on the intended use of results of evaluations. Examples of systems are the performance-monitoring system, the `experimentalist' system and the evaluation-accreditation system. Several problematic aspects of these systems are described, making it relevant to study them. One of these is the danger that evaluation systems breed (new) evaluation systems.another problem is that these systems may produce largely routinized information relevant for day-to-day practices and single-loop learning processes, but which is of little relevance for fundamental reassessments of policies and programmes.