Ambiguity refers to the absence of an overall frame-work to interpret situations. Multiple meanings can exist side by side, and this often causes confusion and conflict. Ambiguity differs from uncertainty. Whereas uncertainty—a shortage of information—can be reduced by facts, new and more objective information will not reduce ambiguity because facts do not have an inherent meaning. Ambiguity poses particular problems for evaluators: How is one to evaluate a policy or program if the underlying concept has no clear meaning? A possible way out is to conduct are responsive approach that takes ambiguity as a departure point for reflexive dialogues on the evaluated practice.