Links as Definitions

While there are many ways in which the Web can be used to can enhance technical learning, we will focus here on a single goal:

Semi-automatic linking of phrases in on-line documents to definitive home pages

To motivate this goal, consider a student encountering an unfamiliar term in an on-line tutorial. The student will want to click on the term to find out what it means. (Multi-word terms may be first selected with the mouse.) For this student, the link should answer the question ``What is this?''.

Of course, a more experienced reader might already know what the term means, and might instead want more advanced information, pointers to related information, and so on. For this reason, a good ``definition home page'' should include more than just a definition. On the Web, convenient pointers to all kinds of further information can easily be provided. All anticipated questions and interests can be accommodated economically via links.

A definition home page is needed for every important term in a given field of knowledge. Fortunately, only one can suffice on the Web in each language. This is not an insurmountable task compared with the effort expended to create the existing literature in any given field. In principle, we can divide up the labor so that each educator or specialist is responsible for only a small number of definition home pages. It is likely that educators and researchers will compete intensively for the privilege of serving home pages on selected topics in their field of expertise. Such global competition will also likely ensure that the ``winning definitions'' will be freely accessible. All it takes is one excellent free contribution anywhere in the world to render most others obsolete. Contributions of this nature are already appearing rapidly in many areas, particularly in technical areas, and so there is already a need for something like the Open Dictionary to organize and rank competing offerings.

It is perhaps worth emphasizing here how the Web has completely redefined what it means to ``look something up.'' Before the Web and inexpensive hard disks, the largest unit of reference was a book. Now it is the Web as a whole. One of the larger examples of a book is the Oxford English Dictionary (OED). To accommodate the full English lexicon and its etymologies (still excluding most modern technical terms), the OED has resorted to extremely thin paper and printed type so small that a magnifying glass is required by most readers. Even so, the actual definitions remain somewhat terse, and little reference to related information can be found (although there has been an attempt to make a hypertext version of the OED). We are no longer constrained by the size of a printed book. On the Web, a definition can be an entire website devoted to one topic, and pointers to additional information are immediately accessible rather than requiring physical look-up at a library. A single definition home page can now encompass the equivalent of any number of physical books. Since quantity is now unrestricted, quality of will become more important than ever. Quality pertains not only to the lucidity of tutorial expositions themselves, but also to the organization of topic home pages in a top-down manner so that every conceivable reader is routed via one or two clicks to the appropriate level and scope.