This 3-part article represents an effort to confront 3 large lacunae in the research on reading fluency: definition, component structure, and theory-based intervention. The 1st section describes several historical approaches to fluency and the components of fluent reading that are implicit in these approaches. We then present our own developmental- and component-based definition of reading fluency. In the 2nd section we discuss how different types of current fluency interventions correspond to particular components in fluency's structure and to particular phases of its development. The last section presents an overview of an experimental fluency program that attempts to address multiple components in the development of fluent reading. Finally, we argue that increased exploration of the issues surrounding fluency and comprehension will contribute to our understanding of both reading development and dyslexia subtypes.