After creating solution concepts during the creation phase, choosing for the specific solution concept based on criteria (as mentioned in Sect. 6.6 ), and elaborating the chosen solution concept, we will look here how to evaluate the solution concept(s). Two remarks have to be made here. In the first place, evaluation can already be considered during the creation phase. Venable et al. (2016) call this ‘ex ante evaluation’. Evaluation of the selected solution concept during the ‘evaluation phase’ is called ‘ex post evaluation’ (Venable et al., 2016). The second remark is that with evaluation, more in particular during the evaluation phase, we also validate the solution concept. Besides the evaluation forms presented in this chapter which serve as a validation for the solution concept, there are other validation methods, as presented in Chap. 10 , which can be seen as quality indicators for the conducted research. Concerning evaluation in design science research, categories distinguish the reasoning and strategies for evaluation, including when to evaluate, why to evaluate, and how to evaluate.