A greatly expanded revision of the author’s previous Hypertext and hypermedia [1], this volume reflects the growth in the subject discussed. In l990, Nielsen could provide a credible survey of the field in the scope of 268 small pages. The new volume is much larger, and though it follows the same outline as the earlier book (even to the point of duplicating many chapter and section titles), the new material justifies the revised title. The book is copiously illustrated, with over 140 figures and tables, including many screen dumps from actual systems.

The first four chapters are an introduction, and borrow heavily from the earlier book. Chapter 1, “Defining Hypertext, Hypermedia, and Multimedia,” builds on the common notion of a document that can be read nonlinearly, and illustrates the multimedia nature of current technology through adventure games and interactive video. Chapter 2, “An Example of a Hypertext System,” walks the reader through Nielsen’s widely-distributed trip report on the first hypertext conference (Hypertext ’87), which was implemented in  HyperCard.  Chapter 3, “The History of Hypertext,” traces the technology from Vannevar Bush’s concept of the Memex to the commercial explosion of applications in the l990s. Chapter 4, “Applications of Hypertext,” is the longest chapter in the book, and illustrates how hypertext has been deployed in support of computer work (such as documentation, software engineering environments, and help desks), business, knowledge work, education, and entertainment.

Chapters 5, 6, and 7 look at important technical issues in modern hypertext implementations. Chapter 5, “The Architecture of Hypertext Systems,” reviews the basic concepts of nodes and links, and discusses techniques for “open hypertext,” which seeks to integrate hypertext capabilities with the user’s complete computational environment. Chapter 6, “Hardware Support for Hypertext,” focuses on the capabilities and limitations of computer screens and pointing devices and highlights the importance of CD-ROMs for the recent explosion of large hypertexts. Probably the biggest event in hypermedia since the publication of the earlier book is the explosion of the World Wide Web, the central subject of chapter 7, “Hypertext on the Internet.” In addition to a detailed explanation of the Web and its underlying Hypertext Markup Language (HTML), the chapter explains other lesser-known but technically more advanced approaches to network-based hypermedia.

Nielsen’s distinctive niche in the hypermedia community is his careful attention to the match between the computerized system and the human user, and chapters 8, 9, and 10 draw on this expertise to provide a valuable guide to usability. Chapter 8, “Coping with Information Overload,” is especially pertinent in light of highly distributed network-based hypertext systems. It describes experiments with “the n of 2n approach,” in which users are presented with about twice as many objects as they are expected to select. Chapter 9, “Navigating Large Information Spaces,” gives examples of devices, such as overview diagrams and navigational metaphors, that help users to cope with large webs of material. Chapter 10, “Hypertext Usability,” includes both results from benchmark experiments and informal anecdotal reports.

The next two chapters deal with the problem of generating a body of nonlinear material in the first place. Chapter 11, “Multimedia Authoring,” focuses on the problems associated with writing new material for hypermedia, while chapter 12, “Repurposing Existing Content,” examines issues associated with converting existing bodies of information to hypertext. Chapter 13, “The Future of Multimedia and Hypertext,” candidly reviews the success of Nielsen’s predictions in the earlier book and offers a new set of projections, including interesting speculation on whether the field of hypermedia publishing will be dominated by a few titans or a swarm of cottage producers.

As in Nielsen’s previous volume, the bibliography is not just a list of titles, but a sizeable text that is worth reading in its own right. It provides a brief summary of each of the more than 450 books and papers referenced, and discusses surveys of the field, societies and conferences, journals, magazines, videotapes, information about the Internet, classics of the field, and unusual future visions. The index includes cross-references to the bibliography for many of the concepts listed. This coherent, readable, well-documented account of the state of the field will be an invaluable desk reference for both students and practitioners.