This chapter discusses the role of navigational aids in the comprehension and use of complex hypermedia documents. Navigational aids constitute a broad category of verbal and graphical devices ranging from local cues, (e.g., headings, introductions and connectors) to global content representations (e.g., tables, outlines and concept maps). Text-processing research has demonstrated that the principled use of cues and content representations improves learners' comprehension and memory for text. Navigational aids are also helpful in hypertext-based learning, provided that the aids are considerate to the users' needs. We review relevant research studies indicating that the benefits of various types of content representations vary as a function of the reader's expertise and purpose. We offer an explanation in terms of conceptual activation in memory, based on behavioral and computational evidence. Research results suggest that any attempt to optimize the design of instructional hypermedia systems should consider readers' prior knowledge, the contents to be presented, and how the contents will be used.
Introduction to Navigational Principles
Information resources, whether in print or online, play an increasing role in learning communities. Students in secondary and higher education are now commonly asked to learn by interacting with vast repositories of documents, in the context of more or less specific study assignments. For example, students may be asked to gather information about the causes of the 19th-century Irish potato famine, or to find out how the sea otter catches her food. Such tasks involve not just reading, but also searching and navigating multiple sources of information.