Digital Indexes in eBooks

With the shift to digital, user accessibility to content is more important than ever. After all, digital non-fiction books (Iike their print counterparts) are still about discovery and learning, and time-pressed users overwhelmed with information need a quick way to zero-in on the most important concepts and transform information into knowledge. Whether the book is a textbook, a reference work, a test-preparation guide, or a treatise on marketing, “Search” and resulting “hits” are not enough. Oftentimes users don’t even know exactly what they are looking for. A well-constructed index (whether print or digital) provides a structured overview of the material and allows the user to locate specific information in the context of the entire book, thus aiding in the discovery process.

Ideally, hyperlinks from the index should go to the exact location in the text. In the real world most publishers follow an InDesign to PDF workflow, and the digital version of the book is created from the PDF by the compositor. Most digital indexes that are “converted” from print merely bring the user to the top of what corresponds to the print page. This is the minimum standard for digital (hyperlinked) indexes. Hyperlinks from the index locators to EXACT places in the text would be even more useful to the user. Unfortunately, this is often not practical because of the extra work involved in inserting individual index tags into the layout program (for example, InDesign). A notable exception is an XML-first workflow. This workflow, used by a handful of publishers, allows the insertion of index tags just once, in the XML file, before it is output to PDF, web, and other digital formats.