Books are based on specific technology - paper, movable type, etc. Accumulated deep understanding of the technology has made the codex into a superb artifact. This understanding is manifest in the design and structure of printed books, the organization of ideas into chapters or articles, the use of front matter and indexes, and in the graphical design. Much current research in digital libraries and electronic publishing attempts to mimic books and journals. Formats such as SGML and PDF were developed for this very purpose.
Most electronic journals replicate conventions from the print world.
These are important interim steps to smooth the transition to on- line information, but they remind me of Gutenberg's fonts, which were designed to mimic manuscript. Searching may be the most confusing of all the topics in digital libraries. Some of the confusion comes from a clash of personalities, between the traditions of cataloguing and indexing, and the optimism of researchers in natural language processing. However, the issues are more fundamental. One important issue is that information is changing.