Abstract
The question whether research techniques are producing artifacts or data is often a crucial one for scientists. The potential for artifacts results from the fact that generating data often requires numerous procedures that are often brutal, poorly understood, and very sensitive to details of the procedure. Through a case-study of the introduction of electron microscopy as a tool for studying cells, I examine how scientists judge whether new techniques are introducing artifacts. Three factors seem to be most salient in their judgments: determinateness of the results, consilience of different procedures, and ability of the results to fit into emerging theories.