The advent of Web-based instruction, which relies upon hypertext models of interaction and design, reemphasizes the need for a clear understanding of how learners process and encode information presented in Web sites intended for instructional purposes. The unique nature of Web page design, mandated by constraints in the technology which limit student interactivity, and yet which support divergent exploration, necessitates a deeper consideration of how learners interact with various Web site design factors. The purpose of this chapter will be to address the cognitive implications of those factors. This chapter will not focus on specific graphic layout and design criteria or visual display specifications that have been extensively covered in the research literature on computer screen design. The intent, rather, is to review and discuss the major theoretical and design issues impacting contemporary instructional Web page design. It is essential however, to understand the basis for much of the Web page design that occurs currently, and that stems from much of the earlier work in computer screen design.