A significant amount of attention has been placed on IS Evaluation within the literature over the years and much has been written. In this paper we review the advancement of research in this area. We found however, that only a limited understanding of the phenomenon exists and only modest progression has been made: while the literature states the importance and objectives of IS evaluation, and its complexity and problematic nature,, not all concepts related are clearly defined. In addition, several taxonomies for classifying evaluation approaches exist, but there is no agreement as to which of these is acceptable for the entire research community, let alone for practice. Our review also shows that the literature is replete with reports of what industry uses in terms of evaluation approaches and methods, but that there is a lack of thorough accounts of actual evaluation practice, what works well and what the concrete problems associated with it are. Finally, we also found that the role and interplay of formality and intuition in IS evaluation is controversially discussed. On this basis the paper identifies a research gap and argues for more detailed empirical studies of actual evaluation practice to advance the field of IS, both in theory and practice.