By Pierke Bosschieter, 5 February 2026
The index is one of the most underestimated parts of a book. When it is missing, readers notice immediately; when it is poorly made, they notice even more. A bad index sends readers on wild goose chases, points them to pages that say nothing useful, or simply fails to acknowledge what the book is actually about. A good index, paradoxically, disappears entirely. It does its job so quietly that few readers stop to consider that it was designed, structured and written by a human who made hundreds of small, deliberate decisions.
For editors and translators, this should sound familiar. We all work with texts in ways that are meant to be seamless and invisible. When the work is good, no one comments on it; when it is bad, it becomes impossible to ignore. Indexing belongs to this same family of text-based crafts, even though it often sits at the very back of the book and well outside the spotlight.
The key difference is that indexers do not work on the narrative itself, but on the infrastructure around it. If the text is the building, the index is the floor plan and the signage. Readers may admire the architecture, but when they are lost – or in a hurry – they reach for the map. A well-made index does not ask for attention; it simply gets the reader where they need to go.
Words versus concepts
One of the most persistent misconceptions is that an index is merely an alphabetical list of words extracted from a text. This idea is reinforced by software that can generate something index-like at remarkable speed. What such tools cannot do is understand what a text is about. Indexing is not about words; it is about concepts. It involves deciding what is significant, what is secondary, how ideas relate to one another, and which terms readers are most likely to use when searching for information.
That conceptual focus makes indexing closely related to editing and translating. Like editors and translators, indexers read analytically and critically. They interpret meaning, register nuance, and consider the expectations of a specific audience. The additional layer is usability. Indexers constantly shift perspective from writer to reader, asking not ‘what did the author mean?’ but ‘how will someone try to find this?’.
This shift in perspective also explains why authors themselves are usually not the obvious choice to create the index for their own work. Authors are deeply involved in their text. They know its structure, terminology, and internal logic too well. That familiarity makes it difficult to step back and see the book as a user would. Indexing requires distance and a willingness to question the text’s assumptions. Much like self-editing or self-translating, author indexing often prioritizes intention over accessibility.
Indexing requires training
What is less widely known is that indexing is not an improvised activity guided by personal preference. Professional indexers work according to established rules and conventions, including international standards such as ISO norms. These norms address matters such as structure, consistency, cross-referencing, and clarity. They exist for the same reason editorial style guides exist: to ensure that readers can rely on predictable, intelligible navigation. A recent example of this ongoing standardization work can be found in the NISO recommended practice ‘ANSI/NISO Z39.4-2021 Criteria for Indexes’. Indexing may look creative, but it is creativity exercised within a clearly defined framework.
The craft can also be learnt. There are structured training routes, including well-established online courses in the UK and US, and indexing is supported by professional societies across the world. These organizations provide education, guidance, mentoring, and a shared understanding of best practice. In the Netherlands, indexers are represented by the Netherlands Indexers Network (NIN) while many international indexers are affiliated with bodies such as the Society of Indexers (SI) and the American Society for Indexing (ASI). Their existence underlines a simple fact: indexing is a discipline with its own standards, not an afterthought to be tacked on at the end. If you are considering adding indexing to your professional portfolio, a short course with Sylvia Coates can offer a practical introduction and help you assess whether indexing is a good fit for you.
The skills required reflect this. Indexers need excellent reading comprehension, strong analytical abilities, and the capacity to think in systems rather than sentences. They must be consistent without being rigid, precise without becoming pedantic, and flexible without losing structure. They also need patience, concentration, and a certain tolerance for working in obscurity. When an index functions perfectly, it rarely attracts praise.
Sister crafts
Indexers also share challenges that editors and translators will recognize immediately. One of these is competition from AI. Automated tools can produce indexes quickly and cheaply, and in some contexts, they may appear adequate at first glance. What they lack is conceptual understanding. They recognize surface language rather than meaning, and they have no sense of how readers search, hesitate, or misunderstand. As with machine translation and automated editing, AI can be a useful aid, but it cannot replace informed human judgment.
Another familiar challenge is competition from untrained providers – the beunhazen – who believe that ‘anyone can make an index’. In a narrow sense, this is true. Anyone can produce something that looks like an index. The problem is that poor indexing damages books, frustrates readers, and undermines the profession itself. Editors and translators have long experience with this dynamic and its consequences.
Despite these pressures, the index remains essential. In an age of information overload, access matters as much as content. A well-constructed index increases a book’s usability, extends its lifespan, and supports serious engagement with complex material. It turns information into something navigable rather than overwhelming.
Indexing is therefore not a marginal activity, but a sister craft to editing and translating. It is governed by standards, supported by training, and sustained by the same conviction: quality is the result of expertise, not automation or convenience. And, like so much human work done well, it is mostly invisible – until it isn’t there.
Pierke Bosschieter has been a professional indexer since 2005. She specializes in Middle Eastern studies. She’s one of the coordinators of ICRIS (the international coordinating body for indexers) and is on the editorial board of The Indexer (an international academic journal). She’s a driving force behind NIN, and is mentoring beginning indexers and trying to bring awareness of indexing to the Dutch publishing industry.
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Blog post by: Pierke Bosschieter |
