7.2 On-Line Help

On-line help is the great unfulfilled promise of computer applications. Surely the power of a computer to search, reorganize, customize, and even animate information should make it possible to help the user far more effectively than with printed paper, a centuries-old technology. Well, maybe someday it will. But except for a very few products that have required extensive effort to develop, such as Bellcore's "SuperBook" and the Symbolics Lisp Machine's "Document Examiner," the attempts to deliver large volumes of information on-line have generally been shown to be no more effective than traditional books and manuals. This is the case even though the on-line systems offer hypertext features such as word search and linking to related topics. Without these features, on-line text may well be less effective. For basic on-line help systems the message is this: If you need to present more than a brief description of a system feature, don't rely on on-line help.

The ineffectiveness of lengthy on-line help files is probably the result of several factors: Text on a computer screen is usually less readable than printed text. Less text is presented on the screen than on the printed page. It's much easier to get lost while navigating through screens of text than while thumbing through pages of a book. Screens don't update as quickly as pages turn. You can't circle a word in on-line text with your pencil, or dog-ear a page. The help window or screen often covers the part of the interface that the user has questions about. And, people haven't practiced reading on-line text for most of their life, as they have with printed text. The combined effect of these problems over-balances all the advantages that are associated with on- line text.

But while on-line help isn't the place to put the entire manual, it does have potential uses. It's an excellent place to put brief facts, "one liners," that users need frequently or are likely to forget. A prime example is the definitions of function keys or keyboard equivalents to mouse menu items. On many systems, these mappings are shown on the mouseable menus, an effective form of on-line help for users who are interested. Another example is a list of command options for a command-oriented system. Users often know exactly what they want to do in these systems, but forget the exact spelling or syntax of a command. A SIMPLE display of that information can save the user the trouble of digging out a manual. For these and other simple facts, on-line help is usually better than a reference card, which is easily lost or misplaced.

The most common failure of on-line help is to provide too much information. It's not that users could never apply the extra information, but that they often won't be able to find what's immediately relevant within the extra text. The solution is to cut the on-line text to a bare minimum. As a rule of thumb, a line of information is useful. A paragraph of text is questionable, although a table with several lines may work. An entire screen should usually be relegated to the manual.

To go a little beyond the rule of thumb, you can apply a slightly modified version of the cognitive walkthrough to on- line help. Imagine a user with a problem that the proposed on-line help could solve. Ask yourself: Will the user think of looking in on-line help? Will the user be able to find the information that would solve the current problem? And if the user finds the right information, will it be obvious that it answers the user's question? The last two points recall the vocabulary problem, which applies in spades to on-line help systems. These systems can't easily be scanned or browsed, they usually don't have an index, and reading speed and comprehension deteriorate for on-screen text.