8 8 SEEING IS BELIEVING Using Images as Evidence in Evaluation Sandra Mathison As for a picture, if it isn’t worth a thousand words, to hell with it. —Ad Rheinhardt, minimalist American painter Images are evidence; this chapter explores the credibility and usefulness of images as evidence in evaluation. While there are unique features of images, their credibility exists within a larger framework for establishing facts and values. The credibility of evidence and the knowledge it generates is contingent on experience, perception, and social conventions. As such, knowledge changes over time (consider that Pluto once existed as a planet, and now it doesn’t) and can and should be arrived at through many means, eschewing the dominance of any one method or data type. Embracing Feyerabend’s (1975) anarchist epistemology, the notion that every idea or strategy however new or old or absurd is worthy of consideration, we can expand the possibilities for knowing the social world. Credible evidence is not the province of certain methods (such as observations or experiments) and cannot be expressed only one way (such as statistical averages or vignettes). To extend Feyerabend’s notion, credible evidence should be