As with all media, the Internet structures and frames information, rewarding some information search and decision behaviors while punishing others and, thereby, strongly influences evaluation research results and possibilities. Now that the Internet is for many evaluators the information medium of choice, the impacts of the medium on evaluation deserve careful attention. The objective of this article is to lay groundwork for a theory of the impact of the Internet on evaluation and policy analysis. Questions addressed include the following: (a) What is the impact of the Internet on the evaluator's professional role, work norms, and work habits? (b) Does the use of the Internet affect who is an evaluator or the meaning of professional evaluation? and (c) How does evaluation via Internet affect the technical quality and credibility of evaluation? A key thesis is that the Internet compresses information in the sense that it is not always easy to distinguish among information resources and, especially, the authority of the information provider and the nature of the knowledge warrant. On one hand, the Internet's information compression seems to hold potential for the democratization of evaluation. On the other hand, the diminished ability to make quality distinctions about evaluation-relevant information may undercut the legitimacy of evaluation.