At the turn of the century, Dewey advocated learner-centered but teacher-guided education built around efforts to link purpose and structure. For example, he advocated projects like designing a clubhouse because this activity embraced multiple levels of organization and placed students in the role of developing rather than receiving knowledge. Unfortunately, schools rarely have embraced this philosophy, in part because the metaphor of learning in schools is often one of knowledge transmission rather than of knowledge construction (Perkins, 1986), and in part because the construction of physical artifacts often is limited both materially and intellectually. For example, having built one clubhouse, how easy is it to revise, elaborate, or extend it to other constructions? So instead of designing clubhouses and other physical artifacts, Perkins (1986) suggests that teachers and learners design knowledge. The strength of this metaphor stems from its polysemy: Design refers simultaneously to structure and to process. In this chapter, I suggest that a new form of computer-sustained literacy, hypermedia, can be used to foster knowledge design. Accordingly, I describe the development and implementation of a hypermedia authoring environment, HyperAuthor, used by 8th-grade American history students as an instructional design tool. In the process of design, these students developed new ideas about history, and about themselves as authors of knowledge.