Is an index useful in a PDF?
In the age of digital documents, is an index an indispensable element of good technical documentation?
Full-text search appears to have replaced the index. Technical manuals are rarely provided to customers in paper form. PDF, a format for exchanging non-customer-facing source content and a marginally intended printed version, has become the norm. The Ctrl+F keystroke sequence is now a natural reflex for anyone seeking information.
Text intended for the web employs a wide range of terminology to enhance visibility on search engines. Using synonyms is essential to provide potential readers multiple paths to relevant information. Thus, search engines have rendered the index obsolete.
However, if technical documentation uses consistent terminology, full-text search effectiveness diminishes: if the technical writer uses only the term directory, readers searching for folder will miss the information they need.
In this case, a well-crafted index is invaluable. The challenge lies in the significant effort required at the project’s end, just before delivery. A poorly created index benefits neither the customer nor the company.
Paradoxically, an index is more useful for high-quality documentation than for inadequate documentation (with inconsistent terminology). However, its cost-to-benefit ratio is low. It’s a luxury companies rarely afford and not the primary quality aspect to prioritize. An index is the icing on the cake of technical documentation, but the most important element is the cake itself.