Representing data. or depicting research evidence so that others can appreciate and use it. has always been a major research issue in social science and education. In experimental and survey social science, researchers construct variables to represent the phenomena under investigation, and they worry about whether their variables adecli~ately capture what is going on. In ethnographies and case studies, researchers rely on descriptions of first-hand experience, concepts from the literature. excerpts from field notes, and quotes from interviews to represent the people or events of interest; and they also worry about how well their representations capture the phenomena under investigation. If representations of research evidence are not in some sense trustworthy, findings based on them will be suspect.