It is true that common indexing wisdom is to avoid repeating locators within an array. Repetition, with locators duplicated across subheadings, can bloat an index. An array may be difficult to read, or confusing to readers, if there are too many similar subheadings side-by-side. If there is a strict length limit, there may also not be enough space for duplication.

And yet, as with many conventions in indexing, “it depends.” I recently wrote an index in which I did consider repeating locators within an array. I think it is worth teasing out why this may sometimes be appropriate.

Framing Discussions

To start, it is important to recognize that discussions can be framed multiple ways. This affects how subheadings are phrased.

One option is to state the literal concept, object, organization, or person that is being discussed. For the book I recently indexed, which was about Anglican Church leaders and fertility-manipulation schemes during the interwar period, this could be something like,

birth control: Anglican leaders on

This tells the reader who is commenting (Anglican leaders) and what they are commenting on (birth control), but it does not tell us anything about the substance of the discussion.

Another approach is thematic, to focus on that substance. For example,

birth control: class and; empire and

These two approaches can also be combined, though such subheadings can become unwieldy and each element of the subheading may not appear on every page. For example,

birth control: and Anglican leaders’ concerns about class and empire 

My point here is not to advocate for one framing over another. I use different approaches, often within the same index. It depends on what I think it most relevant for the reader and the array. To cut down on length and to keep arrays succinct, it often helps to pick a single frame. As is oft said, the goal is to point readers to the information, not to rewrite the text.

Other times, however, it may make sense to include multiple frames—multiple subheadings—because the different frames carry equal weight and because the discussions—and locators—while overlapping, are also distinct. This can help tease out the different elements, especially when discussions are complicated and intertwined. So, something like,

birth control: Anglican leaders on; class and; empire and

Alternate Entry Points

An alternative to having parallel subheadings and duplicate locators within an array is to create entry points elsewhere. Perhaps there is not enough space in the birth control array to include subheadings for class and empire, but those can both be (and should be) main entries in their own right. When considering the different elements of a discussion, and the different ways a discussion can be framed, think about what other headings and subheadings can be created elsewhere. An index is the perfect place to deconstruct and scatter discussions.

Multiple Discussions Per Page

It may also happen that a single page contains multiple distinct discussions. This is especially true the more words there are per page, depending on how the book has been typeset. If this is the case, then index to the discussions. Don’t worry if locators are duplicated. 

The trick here is distinguishing what is truly a distinct discussion or fact, rather than a granular subset of the same discussion. Does the discussion still hold together when you telescope out?

Focus on the Story

Lastly, consider the story that the array needs to tell. What is it, about this subject, that is important for the reader to know? This is not about rewriting the book in the index, but rather about effectively pointing readers in the right direction. Having a focus is also relevant for space, both because space for the index may be limited and in the sense that a succinct array is easier to scan. 

This also comes back to framing. What is the most effective frame for readers to recognize what they are seeking? As mentioned, often a single frame is sufficient, focusing on whatever is most relevant. In other instances, it may be better to include multiple frames if they hold equal weight. Either way, test the subheading(s) against the larger story or point that the book is making about that topic. 

Repeating locators within an array, across two or more subheadings, is usually a question of how that information is being framed. It is often best to avoid duplication, to avoid similar, parallel subheadings or an array that is too long. In other instances, in which discussions are complicated with intertwined subjects and themes, parallel subheadings may be justified. It is a matter of seeing the whole story that needs to be conveyed, and then deciding the best way to point readers towards that story. As with so much when indexing, it is less a question of right or wrong, and more a matter of weighing the relative merits and applicability of different approaches.

Today’s question comes from Winona, and references a previous reflection I wrote. Winona asks:

In your post on the subjective side of indexing, you write that two indexers can produce different indexes for the same book, but that there should still be significant overlap because the text’s aboutness remains the same. Is there any practical way to quantify that overlap? For instance, after accounting for defensible differences in wording, formatting, and structure, should a certain percentage — say, 50% or more — of top-level entries overlap?

Thank you, Winona. That is an excellent question. If a certain amount of overlap is expected, it is reasonable to ask if that overlap can be quantified.

My short answer is no, I do not know if there is a practical way to quantify that overlap. I am also not sure if it is possible to ever fully quantify it. I imagine a lot would depend on the subject matter and type of book, as well as, of course, the subjective approach each indexer brings.

To attempt a quantitative answer, I think you would need to analyze multiple indexes from multiple indexers across several books. I have not done that research. If someone else would like to do so, I think the results would be fascinating.

I will, however, still attempt a response. While I do not have hard numbers, this is a question worth considering and I have some thoughts about what to look for in terms of overlap. I am mostly drawing upon my experience working with subcontractors. While subcontracting is not an exact comparison, since there is usually one indexer providing direction, subcontracting does involve two or more indexers working on the same text.

I also highly recommend this article by Jolanta Komornicka, recently published in The Indexer. Jolanta convened two panels, at two different conferences, for which participating indexers indexed the same book. Jolanta attempts to answer this very question, of how similar or different the resulting indexes are. Definitely worth checking out.

When considering overlap between indexes for the same book, I want to distinguish between main headings and everything else.

At the main heading level, I would expect a high level of overlap. Most terms are not up for interpretation. People, places, organizations, and objects should generally be indexed as written in the text. Concepts which are clearly identified in the text should also usually be indexed as presented.

There is still some room for variation and the indexers’ subjective choices. For example, whether or not to include glosses, and how to phrase the glosses; how to handle synonymous terms; what counts as a passing mention, and, conversely, which are important themes and discussions; and any discussions which are implicit and which require more interpretation. But by and large, I would expect main headings to mostly be similar across all indexes. 

Beyond main headings, I think there is far more room for different decisions to be made. These include:

• Metatopic: How is the metatopic handled?
• Structure: How is information divided or gathered throughout the index?
• Subheadings: How many subheadings are used? Are subheadings mixed with undifferentiated locators? How are subheadings phrased?
• Cross-references: Are cross-references used sparingly or extensively? In which directions are cross-references pointing? Are cross-references used alongside or instead of double-posts?

At the level of structure and subheadings, there are so many different decisions that can be made. There should be recognizable overlap in terms of themes and correspondence to the text, but I don’t know if it is possible to quantify how much overlap or to expect that certain subheadings and arrays will be interchangeable. 

To sum up, I would expect a high level of overlap between main headings, since many terms should be indexed as is. But indexing is a lot more than simply identifying and picking up terms. An excellent index involves organizing all of those terms in a way that is accessible and to highlight the key themes of the book. How all that organization happens is very much subjective. While the indexes should all still clearly point back to the same text, I don’t know if it is possible to fully quantify overlap.

Shifting directions slightly: I think what the creators of AI indexing tools are attempting to do is to quantify or codify indexing decisions. Or at least they believe that a good index is simply the result of following a certain set of rules. But that is not entirely true. Yes, an index is deeply governed by rules and conventions, and an AI tool can probably reproduce those rules and mimic various techniques. But an excellent index is ultimately the result of the indexer’s judgment. It is deciding which rules to apply, and when, and how to combine techniques, and how to make adjustments to fit the material rather than trying to force the material to fit the format. The subjective nature of writing an index, while difficult to quantify and difficult to compare, is also a superpower, enabling indexes and indexers to respond to the text and to readers. 

PS. As I mentioned, I highly recommend Jolanta Komornicka’s recent article in which Jolanta attempts to quantify how similar and different the indexes by her panelists are. You can find it here. If you do not have a subscription to The Indexer, try accessing through your local library. 

Today’s question is a little different in that it comes from a subcontractor I work with. The question was asked in response to a specific piece of advice that I gave for a previous project we worked on together. My thanks for asking and for suggesting this might be a good fit for a Q&A. 

With some modification to remove references to the specific project and so that the question is more broadly applicable:

How do you know when to use terms drawn directly from the text, including chapter titles and headings? In some of the books I’m indexing, the headings make for terrible terms.

Thank you for the question. I did previously advise that headings within the book can be a good source for main headings and subheadings in the index, and that it is not always necessary to reinvent the terms used in the index. That said, I also agree that headings within books are not always useful.

I think this is a good example of a conditional rule. If the headings and terms used in the book clearly describe what is discussed, then use those terms in the index. If the terms used in the book are not clear, then you may need to apply your own.

There are a few competing interests to keep in mind.

On the one hand, using terms from the book helps readers more easily see the connection between the index and the text. The reader does not need to make the mental leap from one term to another, to understand that both terms mean the same thing.

Certain terms can also be considered jargon or terms of art—specialized terms specific to that discipline. These terms are also important to pick up as is because the audience will likely be expecting them. The indexer should not try to reinterprete or rewrite terms of art.

Using terms from the text is also easier for the indexer. It is less time and effort spent on thinking up alternative phrasings. So go ahead and make your work a little easier by following the text’s lead. 

On the other hand, not all books lend themselves to clear terms. I find that certain disciplines and genres, such as in the social sciences or for guide or reference books, follow conventions which encourage a clear structure and clearly written headings. In other disciplines and genres, books can still be clearly written, but there seems to be more leeway for the author’s discretion. Authors may opt for descriptive headings which are fun to read but are not written in plain language. For those books, the indexable term which describes what the discussion is actually about may be buried or it requires the indexer to read between the lines.

Finding and selecting terms also brings to mind the issue of plain language, which Iva Cheung has done a lot of work to raise awareness of among Canadian indexers. It is my belief that the index, as a separate document, should be clearly understandable on its own. While the index is obviously intertwined with the text and ideally should mirror terminology, if the text is not clear, then the indexer should step in and find appropriate terms which are understandable to the audience. 

So when selecting terms for the index, first assess how the book is written. Are headings clearly written and accurately describe what each section is about? Are key terms clearly indicated in discussions? If yes, go ahead and use the language in the book. No need to intervene further.

If the answer is no, then it is time to dig deeper to see if the key terms are buried. Or, do some research or check in with the author to identify terms of art. Or, engage in some translation to clearly describe what the discussions are about. Intervening to rewrite terms takes a bit more work and should be a last resort, but may sometimes be necessary. 

I had a lot more to write than I initially thought about how I use, or don’t use, cross-references, which is why I have split these reflections into two posts. Cross-references are a versatile tool for redirecting readers around the index. They highlight that beyond alphabetical sort, which imposes a default structure, the structure of the index should be deliberate. The decisions on where and how to phrase and place entries should be conscious, to facilitate the reader’s use of the index. Cross-references support that structure by making sure that readers get to the right place. 

Today I’m going to discuss general cross-references, cross-references from subheadings, and cross-references to and from acronyms. 

General Cross-References

Beyond redirecting to specific entries, cross-references can also redirect to a larger category. For example, “Canada… See also specific prime ministers” or “periodic table… See also specific elements.” This works best when readers can reasonably be expected to know who or what might be included in that category, and if there are several headings within that category, leading to a long list if all hits are included. 

If there are only a few possible cross-references, then I think it is better to list them individually. A general cross-reference implies several potential arrays, and if that is not the case, better to be upfront with the reader and not unintentionally mislead. Similarly, if the audience may not be familiar with the category, a general cross-reference could be a dead end rather than a portal.

I do use general cross-references if the above two conditions are met, but I don’t use them very often.  

Cross-References from Subheadings

Cross-references can also be attached to subheadings, rather than being placed at either the beginning or end of the array. This approach is discussed in the NISO Z39.4-2021 indexing criteria, released in 2021, which is when I became more aware of the practice.

I do sometimes include cross-references from subheadings. There are times when that makes the most sense, given the relationship between cross-reference and (sub)heading. Some indexers are proponents of placing cross-references at the subheading level, I think under the rationale that the more granular the placement, the clearer the relationship. There may also be the assumption that readers will be expecting or searching for certain subheadings, even if the information is actually elsewhere in the index.

While I agree that the relationship between cross-reference and (sub)heading should be clear, I also think that arrays should be easy to scan. I also think that given how indexes are typically written, most readers have been trained, through use, to look for cross-references at either the beginning or end of arrays. So while cross-references at the subheading level does have a place, I’m not convinced it is always or often the best choice.

I’ve noticed two problems in how cross-references from subheadings can be used. The first is that cross-references can become buried. They can be more difficult to spot because they are surrounded by other subheadings and locators. 

The second problem is that the array can feel chopped up, especially if multiple subheadings within the array are cross-references. This is often a scenario of cross-references such as, “financial planning: accountants (see accountants); pensions (see pensions); taxes (see taxes)….” For me, that kind of repetition takes up more space and is difficult to scan, especially if interspersed with locators. I think it takes up less space, is easier to scan, and the relationship between heading and cross-reference is still clear if all of the cross-references are gathered together at the end of the array, as in, “financial planning…See also accountants; pensions; taxes.”

So when do I use cross-references from a subheading? I am more likely if there is additional information I want to alert the reader to, as in, “financial planning: accountants and, 34-35, 64, 68 (see also accountants)….” In that scenario, the subheading is necessary for the locators specific to that relationship, and there is additional information elsewhere that I think readers might also want to know. But even then, balancing against potentially burying the cross-reference, I may still place the cross-reference at the end.

Index format can also play a role. Cross-references from subheadings are more likely to be buried and be difficult to scan in run-in format, where there are no visual breaks between subheadings. These problems are less noticeable when using indented format. So when considering where to place subheadings, also consider the impact that format may have on the reading experience.

Cross-References To and From Acronyms

Cross-references can also be used with acronyms. If, for example, there is an entry for “Atomic Energy Commission (AEC),” should there be a corresponding entry for “AEC. See Atomic Energy Commission”?

When I first began indexing, I was meticulous about making sure that headings with acronyms were either double-posted or cross-referenced. I think I saw that somewhere as part of indexing best practices. Until I received pushback from an author. The book was on the health care system in Nova Scotia. It contained so many acronyms. The author pointed out that all of the duplicate arrays made the index far too long and difficult to use, and that most of the acronyms sorted near the spelled-out names anyway. I had another look at the index and decided that the author was right. Since then, I’ve mostly stopped double-posting or including cross-references from acronyms. I don’t think it is necessary.

I do have two exceptions to that rule. The first is if the full name and acronym don’t sort close together. A few years later, I indexed a different book on the health care system in Mexico. Again, a lot of acronyms. This time, I believe the acronyms corresponded to the Spanish name of the organization but the spelled-out name was the English translation. For example, “National Commission for Medical Arbitration (CONAMED).” No relationship between the acronym and full term, and so double-posting or cross-references was important to serve readers searching either way.

My second exception is if I know or suspect that readers are more likely to search for the acronym, or if I’m honestly not sure which way readers will search. In a recent index, the author almost exclusively referred to a number of companies by their acronyms. I’m not sure if those companies are commonly known by their acronyms, but I figure anyone reading the book will probably think of the acronym first, so for those, I decided to either double-post or include a cross-reference. For example, “AEP (American Electric Power)” and “American Electric Power (AEP).” 

As I mentioned above, cross-references are versatile. They reflect that an index is multi-dimensional. An index is more than a list that begins at A and ends with Z. Rather, an index is an interwoven series of entries and arrays which can require navigational aids. Cross-references are the primary means by which to redirect readers to the right place and to additional information.

It is a big book, and it is taking a while to get through. It is also not the only large volume I’ve indexed this year. I feel like I’ve done more than usual, including an Oxford handbook on Baptist studies, an edited collection on Black Canadian art and literature, and a biography of Canadian poet Margaret Avison. These are books that are the equivalent of two or three regular-length volumes. 

Large books can be challenging to index. I have a theory that the length of the index grows exponentially with the length of the book (while, maybe not quite exponentially, but the length does grow), because the longer the book, the more details there are to index, the more locators there are, and the more likely subheadings are needed. Subheadings take up more space and take more time to write and edit, and so the work goes on and on. Also, the larger the book, the more there is to keep in mind. I need to remind myself to reset my expectations for how long the index will take. 

I still want to complete the index efficiently and as quickly as possible, even if the overall number of days and weeks is longer. I’ve been reflecting on what it is I do that is different compared to indexing a shorter book. This is what I’ve gathered so far:

• I write more notes for myself, such as brief summaries for each chapter. Because there is so much more to remember, I don’t want to forget what the beginning of the book was about by the time I reach the end. These notes can also help me see the overarching storyline and themes running through the book.
• I slow down and consciously remind myself to connect back to the big picture. With so many pages to get through, the temptation is to rush and to focus on picking up the easy entries—the low-hanging fruit—of people, places, reactors, chemical elements, etc…Those details are important and need to be picked up, but why are they important? What is the larger discussion or story? I need to make sure that I am creating headings and subheadings at those broader levels too, which means slowing down and understanding what all this is actually about.
• I write subheadings at a broader level. I still pick up plenty of smaller details, but I think broader subheadings are both easier to understand and navigate, and can help keep the array at a manageable length. For main characters and topics, which are going to have a lot of subheadings anyway, indexing less granular may be the difference between forty subheadings versus sixty or eighty, for example. Forty subheadings is still a lot, while still being easier to scan. 
• As I mentioned, broader subheadings can also be easier to navigate. This is because they encompass more and clearly express the larger context. Say a person is involved in constructing the National Research Experimental (NRX) reactor, is quoted reflecting on the reactor, and is also present for the reactor’s meltdown. A more granular approach would be to have separate subheadings for each of those three elements, which are arguably distinct. But in a large array, those three subheadings may sort apart from each other and a reader may not see all of them. Three distinct subheadings also take up more space (see point above). Better, I think, for a single subheading at a broader level, “National Research Experimental (NRX) reactor and,” to capture all of those discussions. The details of construction and meltdown can still be delineated as subheadings under the reactor itself. 
• While indexing at a broader level, I still want main headings and subheadings to be clear and specific. Indexing at a less granular level is not synonymous with being vague. If I go back, say when editing the index, and I don’t know what the subheading is referring to, then I can’t expect the reader to know. The meaning needs to be clear. Which reactor? Which relationship? Which concept or discovery? I try to make my first pass as clear as possible, so I have less work on my second pass and so I don’t leave myself confused when I come back around again.
• Lastly, I want to acknowledge that I use subcontractors on this large projects. I usually ask subcontractors to pick up the names of people, and perhaps also other common elements, such as, for the Avison biography, titles of poems and other works. Having a subcontractor handle these aspects frees up my headspace to focus on the subject entries and the overall structure of the index. It also helps me to get through my own draft more quickly, because I have less to pick up. So many thanks to the indexers I work with. With so much material to get through, I find it can make a noticeable difference.

In one sense, indexing a large book is no different from indexing any other book. I still pick up the same types of entries and my process doesn’t change too much. On the other hand, everything that makes indexing a regular monograph difficult is magnified simply because there is more of it. There are more details, more entries, more subheadings, more cross-references. I find writing the index requires a bit more planning, more notes, and more patience. Because the big picture is so big, it can be difficult to focus on, and so I need to make an even more conscious effort to keep referring back to what the book is about.

The big picture—the story that is being told—is the underlying aboutness, which needs to be visible in the index. I don’t want to get lost while indexing, and I don’t want the reader to be lost either. I need to slow down, think through my decisions, make sure I am seeing as clearer as I can in that moment, so that the reader can hopefully see through me.

Today’s question is about granularity:

How should I judge what level of granular information the reader will be looking for? Too many subheadings with the same locator is a red flag. Is there any other good marker? How do I know if it is too granular, or not granular enough? 

That is an excellent question. Thank you for asking.

I suspect this is a common issue that many indexers face. Part of the challenge is that the answer is so often, “It depends!” It depends on the audience, on the subject matter, on the type of book, and how much space is reserved for the index. Because there are so many factors involved, I’m not sure if I can give a satisfactory answer, but I’m going to give it a try.

What is Granularity?

To begin with, what is granularity, anyway?

Granularity refers to the level of detail. In indexes, this is how detailed entries and arrays are. The level of granularity can vary, from large or wide-angle details to small, specific details. When discussing how granular an entry or index should be—whether it is too granular or not granular enough—this is what we are talking about, the level of granularity. 

As I discuss in my book, I like to conceptualize granularity in terms of the hierarchy of information. Most books contain multiple levels of information, which can be mirrored in the index. At the top—the broadest level of information—is the metatopic, which is what the book as a whole is about. Below that are the supermain discussions, which are the main arguments or points which compose the metatopic. Below those are the regular discussions, which continue to break down the main discussions. At the bottom are the small, specific details which further support and illustrate. Each level is a different level of granularity. 

My view is that all levels of the hierarchy of information should be in the index. A well-written index should be balanced. It is not a question of finding the single correct level of granularity, but of creating entry points for all levels. 

Indexing at multiple levels of granularity provides a number of benefits. It serves different readers, both those searching for specific details and those searching at a broader level. Multiple levels of granularity can also facilitate navigation through the index, whether through nesting more granular subheadings under broader main headings or cross-references from broader to specific arrays. Including both broad and specific headings and subheadings also helps readers—and indexers—avoid getting lost in the weeds. Where I’ve seen granularity go wrong is when the index is primarily a collection of specific details, such that it is difficult to see how the details relate to each other or why they are relevant. Small, specific details can definitely be relevant and important to index, but they also need context, and readers also need context. Indexing at all levels of granularity provides that. 

Telling Stories

I like to think about indexing as telling a story. Each array encapsulates what the book has to say about that particular subject. Especially if the array contains subheadings, the subheadings need to work together to present what the book has to say.

Granularity can factor in a couple of different ways.

One is the appropriate length of ranges. A common rule of thumb is to add subheadings if a discussion extends beyond five pages. This is generally good advice, as searching more than five pages can be a big ask for a reader. But what if the range is seven or eight pages? What if there are no clear points within that range to differentiate into meaningful subheadings? What is space is tight? What if one or more pages are mostly filled with figures? Instead of treating those five pages has a hard limit, I treat it as a guideline. My first goal is to see the whole discussion in context. Sometimes, indexing to the full discussion, even if that means a slightly longer range, is enough. A broader level of granularity points readers to all they need to know.

Another way to consider granularity and storytelling is to consider how broad or specific subheadings can be. If the array is for a supermain discussion, some of the subheadings should probably be for regular discussions. Subheadings can be used to nest levels of granularity. 

To be clear, I am not suggesting that all subheadings need to be of the same granularity or that all subheadings need to be one level below the main heading. Subheadings can serve different purposes, and different types of subheadings can coexist within the same array. It is okay to mix in a few specific details or relationships to other supermain discussions, for example. What I am saying is to pay attention to the story that the array is telling, which is most clearly told in terms of the main points made about the subject and in terms of the relationships between that subject and other subjects. These main points and relationships can often be mapped to levels within the hierarchy of information, which is to say, levels of granularity. 

Spreading Out Granularity

So an index can contain different levels of granularity, and levels of granularity can be used to tell stories and indicate relationships.

Entries and arrays for different levels of granularity can also be spread out throughout the index. It is not always necessary to fit all possible subheadings under a main heading.

Say the array is for a supermain discussion. The book  makes seven main points—regular discussions—about the supermain discussion. Each of those points can become a subheading, which combined provides a solid overview of the subject. Each of those seven points can be further broken down into specific people quoted and illustrations made, but do those people and illustrations need to be in this array? I would suggest not. Keeping this array at a broader level of granularity allows it to be clear and compact. Readers will still find those smaller details if they read through to those pages. Those details can also be standalone entries elsewhere in the index, still findable if readers are looking for them specifically.

I hesitate to be too prescriptive here because every book, index, and array is different. Sometimes arrays do function as a place to gather certain types of detail and it is important to get every mention. But my point remains: levels of detail can be spread out. All information should be findable in the index; it does not all need to be findable in the same place. Play around with how granularity is distributed throughout the index. What can be double-posted? What doesn’t need to be double-posted? How can cross-references be used? What is the function, or story, of each array? 

Audience and Type of Book

The level of granularity can also be affected by the audience and type of book.

I know the common advice is that trade books can be more lightly indexed than scholarly books. I think that is true-ish. My tendency is to write comprehensive, detailed indexes for both trade and scholarly books. Perhaps better to say that scholarly books tend to contain more detail, which lends itself to a more detailed index, while trade books can—but not always—be written in broader strokes. When indexing, match the level of granularity to the book.

How the book is written, and the subject matter, can also affect granularity. Some books are written as broad overviews, whether covering a wide time period, or multiple people, countries, or organizations. For these, keeping subheadings at a broader level can be helpful to prevent the reader—and the indexer—from getting lost in the details. Similarly, if an array has a lot of subheadings—say for a main character or key organization—keeping subheadings at a broader level can be a way to cut down on the number of subheadings needed. Subheadings should still be clear and specific—indexing at a broader level should not be mistaken for being vague. Rather, indexing at a broader level means pointing towards the larger point or context. Specific detail may be better suited for standalone entries. 

How books will be used can also impact granularity. Reference books, for which the index will be a primary entry point, should contain detailed indexes, with lots of subheadings and entry points. Scholarly books often fall into this category as well. Books that are written more as a light or casual read are probably fine with a less granular approach. 

Space Constraints

Space can be a real issue for some indexes. There are not enough lines for the index you want to write. This affects granularity. I think it is still important to try to include entries at all levels of granularity, but if space is a constraint, some entries will need to be cut and compromises made.

If space is tight, I tend to prioritize the big picture. I want the supermain and regular discussions to be clearly present. These are the main points that the book makes, and in my view, the most relevant for readers to find.

Indexing at a broader level can also help save space because the broader entry can incorporate or cover multiple smaller entries. Say there is a discussion about railways, which includes mentions of multiple railway companies. In an ideal index, both “railways” and the specific companies are picked up, but if space is a constraint, I choose “railways” and leave out the specific companies. Readers will still find those companies if they search under “railways,” whereas if I only include entries for the specific companies, readers will have a harder time seeing the whole picture. 

Another consideration is how close or far an entry is from the metatopic. The closer to the metatopic, the more willing I am to keep entries for specific details. The further apart, the more likely I am to cut and instead rely on entries at a broad level. 

When space is tight, I also tend to use fewer subheadings and I allow longer strings of locators. I still try to include subheadings if more than ten or twelve locators, as I don’t want undifferentiated strings to be too long, but subheadings take up space and I’d rather squeeze in more main entries. This is another way to be less granular, by removing the clarity that subheadings can provide. Not ideal, but it can be a worthwhile compromise.

Finding the right level of granularity can be tough. The first challenge is learning to see the different levels. Once you can identify them, it becomes easier to zoom in and out, and to decide how different levels should fit together and be distributed.

To close, I want to reiterate that there is no single, perfect level of granularity that an index should be at. Indexes should contain multiple levels of granularity, and the right mix of levels will depend on the audience, the subject matter, how the book is written, and how much space the index has to play with. But once you can see the different levels, and to see the levels as tools or as building blocks, granularity can be a valuable lens through which to see and construct an index.

Recently, I’ve been thinking about how subheadings can sometimes be repeated and reused throughout an index. This can be valuable to readers, to signal that the same discussion reappears in different contexts or that different people are involved in the same project. This can also ease the cognitive burden of indexing and save time for the indexer. Subheadings do not need to be reinvented for every array.

As a caveat, repeating and reusing subheadings is not going to work for every index. As with any indexing strategy or technique, the first step is to determine if it is applicable. That said, I find this is a helpful strategy to keep on hand.

Repeating and Reusing Subheadings

Subheadings can be repeated and reused in two senses.

The first is to keep in mind or have written down a set of default subheadings that you can draw upon. These subheadings match common discussions or types of material, and so when those discussions come up when indexing, the subheading is readily at hand to plug in.

Some of mine include the following. Depending on the types of books you index, your list may be different.

about

background

education

establishment

introduction

marriage and family

scholarship on

The second scenario for repeating subheadings is project-specific. I find this most often happens for books with significant, overlapping elements. The overlap means that a subheading is likely needed to indicate that relationship. If overlap is extensive, subheadings are likely be reused.

To give an example, earlier this year I indexed Citizens, Scholars, and Friends: Women in the Canadian Association for Adult Education (1935-1965), by Leona M. English (University of Toronto Press, 2026). The book is about the people in the CAAE, especially women, in the context of a number of significant endeavors undertaken by the CAAE. One of those is the journal Food for Thought. I used the subheading “Food for Thought and” under nineteen different people.

To give another example, a few years ago I indexed Decolonizing Independence: Statecraft in Nigeria’s First Republic and Israeli Interventions, by Lynn Schler (Michigan State University Press, 2022). That book discussed overlapping regions, political parties, and politicians. I decided to repeat subheadings across those arrays to give a sense of those interconnections. For example, for the party Action Group and it’s leader, Obafemi Awolowo, the subheadings “Israeli relations and” and “joint corporations and” are repeated, as both the party and leader are involved.

Tailoring Subheadings

When repeating and reusing subheadings, one option is to copy and paste, which is essentially double-posting. That is what I did in the two examples above. But in other cases, while there is overlap that lends itself to reuse, the overlap is not exact. The subheading may need to be tailored.

Going back to the Decolonizing Independence example, the locators for “Israeli relations and” don’t quite match between Action Group and Obafemi Awolowo. Yes, both dealt with Israel and often together, but there are a few places where only one or the other is discussed. So while the subheading can be repeated, locators may vary somewhat.

How the subheading is phrased may also need to be adjusted. Again, looking at Action Group and Awolowo, I used the subheadings, “Action Group (AG): leadership crisis and tensions between Akintola and Awolowo” and “Awolowo, Obafemi: Action Group leadership crisis and conflict with Akintola.” Both subheadings refer to the same incident—a leadership crisis within Action Group and tensions with Akintola—and both use the same key terms, but the terms are rearranged to fit their respective main headings. This still counts as reuse, albeit modified.

Double-Posting vs. Asymmetric

Another consideration when repeating subheadings is, do the subheadings need to be double-posted or can the reuse be asymmetric? By asymmetric, I mean that the subheadings are not mirrored in the overlapping arrays.

In the Decolonizing Independence example, the subheadings are essentially double-posted. While taking into account that the locators and phrasing are sometimes tailored, many of the same subheadings can be found under two or more arrays. This reflects that many of the actors are involved in the same projects and events.

In contrast, many of the repeated subheadings in the CAAE are asymmetric. While the subheading “Food for Thought and” appears under nineteen different people, the array for Food for Thought does not contain a reciprocal list of nineteen people. This has to do with the story that each array is telling. Part of the story, for each person, is the projects they were involved in. For Food for Thought, in contrast, the story is about its establishment, growth, and end; key editors; and key topics and contemporary issues that the journal addressed. While I included subheadings for the key editors, a list of everyone involved would add clutter rather than being helpful.

Connecting to the Larger Story

Taking a step back, the single most important point about subheadings I feel like I keep repeating is the need to connect to the larger context. What is this subheading about? How does it connect to the main heading? Why is it relevant?

The same is true when repeating and reusing subheadings, with the addition that repeating subheadings also reflect broad overlaps within the text. These are relationships that can and should be highlighted at different points. When considering whether subheadings should be double-posted or asymmetric, again, how do these arrays overlap? What is the nature of the relationship? What is the larger story to be told?

To better see if there are overlapping elements and relationships, consider sketching a mind map, as I discussed last month. Take a step back from the index to see the major components and how they relate. The overlap could be specific actors, as in Decolonizing Independence, or the overlap could be more in terms of elements, such as people and projects in the CAAE example.  

It may take some practice to think about books in terms of overlapping elements and to be able to see and formulate repeatable and reusable subheadings. I think it is a strategy worth developing. It can remove some of the guesswork out of subheadings while serving readers by indicating multiple entry points from different angles. 

PS. I discuss the Decolonizing Independence example more extensively in my book, Book Indexing: A Step-by-Step Guide, in the chapter on index structure. Check that out if you want to read more.

Today’s question comes from Kimberly:

 I’ve been giving each heading a subheading right from the start, with the idea that it might be easier to delete unneeded ones than to go back and figure out what they should all be. Do you think this is more likely to speed me up or slow me down?

Great question, Kimberly, and thank you for asking. I appreciate that you are thinking ahead and anticipating that subheadings may be needed. Adding subheadings early can certainly be more efficient, while that information is fresh in your mind, than waiting until later. But is it more efficient to add subheadings to all headings? I’m not convinced about all. 

If you look at most indexes, most arrays lack subheadings. The need for subheadings varies from book to book, but generally speaking, while all arrays should be relevant for the reader and point towards substantive information, only a few arrays are discussed extensively enough, or can be readily divided into subcategories, to warrant subheadings. So spending time creating subheadings for all headings runs the risk of creating a lot of subheadings which will later need to be deleted. Both writing and deleting subheadings takes time (though you are right that deleting can be easy).

A better approach is to try to anticipate which arrays will need subheadings and which will not. This way you can still be proactive about creating subheadings where needed while avoiding unnecessary ones.

Here are two ideas for how to determine whether subheadings are needed:

• Before beginning, get a sense for what the book is about. Maybe scan the table of contents, read the introduction, flip through a few chapters to see how the book is written. What is the book about? What are the main arguments, themes, or topics? For example, books are often organized so that each chapter has its own topic, which will likely need subheadings. Are there types of entries that may require subheadings? In a corporate history, for example, key leaders will probably receive a lot of mentions, enough to need subheadings. In a work of literary criticism, certain key authors and books will probably also need subheadings. Try jotting down a list of likely key topics. When indexing, be on the lookout for them and add those subheadings.
• Run a quick keyword search when you first encounter a name or topic. If you only get three hits, then no subheadings. If you get more than six or ten hits, or whatever your threshold for adding subheadings is, then yes, subheadings are probably necessary. Running quick searches does take a moment, but still quicker than adding and deleting.

If you do realize, partway through, that an array should have subheadings after all, don’t panic. Begin adding subheadings from the point you make that decision. If a few previous locators are still fresh in your memory, go ahead and backtrack to add those subheadings in too. Otherwise, it’s okay to fill in a few missing subheadings at the end, while editing the index. I find that adding two, four, or even six subheadings doesn’t actually take that much time. While it is good to be proactive, missing a few or changing your mind later isn’t that big a deal either. 

Another consideration is that I don’t always know what the subheading should be until I’ve read the whole book and better understand the discussion. So while creating a subheading from the start is a good idea, it is not always feasible. If you find yourself struggling to phrase the subheading or identify what the discussion is about, it’s okay, and may even be faster, to move on and come back to it later.  

Anticipating whether or not subheadings are needed is not an exact science. I still sometimes realize that a discussion is smaller or larger than I thought. But if I can correctly anticipate whether subheadings are needed for most arrays, adding or deleting a few subheadings is still quicker than adding or deleting for all arrays. 

The rough draft is not supposed to be perfect. Yes, trying to get entries right from the start can pay off later with less editing, and I think that maintaining a sense of momentum is also important. I don’t know what is in the book until I finish reading it, and I can’t finalize the index until I know what is in the book, and so while I want to put down my best attempt on the page while drafting, I also want to keep moving until I have a full draft and can assess what I have done. Subheadings are part of this process. Have some strategies to do your best while drafting, while also knowing that it will not be perfect and that it is okay to circle back and revise as needed. 

To kick off this new Q&A, here is a question about subheadings. To summarize, “How can I become faster and more decisive when writing subheadings? I want to index more quickly, and I feel like subs are slowing me down.” Great question, and thank you for asking.

I agree that subheadings can take time. If I have a large index with a lot of subheadings, I anticipate that editing will take longer. I think this is partly because subheadings are more words which need to be written and then revised, and the more words, the more time needs to be spent. It can also take time to decide on the best phrasing for the subheading, especially if pulling the subheading directly from the text is not feasible. When editing the index, it is also not simply a matter of editing individual subheadings, but rather editing the array as a whole so that all of the subheadings work together. All that time spent on analysis and decision making can add up. 

That said, I think it is possible to be faster and more efficient writing subheadings. For me, it comes down to understanding the two types of subheadings, as well as the qualities of a good subheading, so that I can write a better first draft, hopefully resulting in less time spent editing. This is what I will be writing about today. 

(As an aside, I’ve checked Do Mi Stauber’s Facing the Text and I see that she discusses five types of subheadings. I see her point and there is value in understanding the different scenarios in which subheadings can be used. I also think five is a bit too much to remember, and for my purposes I usually think in terms of two types.)

Categorical Subheadings

The first type of subheading is categorical. These are for chunks of information that are all of one type, and are easily defined and identified. For example, works of art by an artist, specific species of plants or animals, products produced by a brand, or types of thermal conduction. For example,

chickadees: black-capped; Carolina; grey-headed

This is essentially a list. Everything within the category is gathered together within an array for the reader to easily scan. The subheadings can typically be copy and pasted from the text. So long as the text is clear, this does not require much interpretation by the indexer; a black-capped chickadee is always going to be a black-capped chickadee.

Descriptive Subheadings

Descriptive subheadings, on the other hand, often requires more work. The indexer needs to interpret the text to identify the underlying aboutness and then write a subheading that both clearly indicates the relationship between the main heading and subheading and why this is of interest to the reader. That is a lot to put on such a short phrase. When I’ve seen subheadings go wrong, this is often where the problem seems to lie. 

Good descriptive subheadings share three main qualities: they relate to the larger context, are at the appropriate level of granularity, and are clearly written.

To illustrate, consider this made-up example:

Washington, George: in battles; communications with; family of; as general; as landowner; as president

How well do you think these subheadings work?

The Larger Context

At first glance, the subheadings appear to be specific, concrete, and concise, which are all good qualities. But how much information do they actually convey?

For me, the first two subheadings, “in battles” and “communications with,” are especially problematic. Which battles are being referenced? For that matter, which war, the French and Indian War or the Revolutionary War? Also, could this subheading be combined with “as general”? Why is being a general relevant? Is the discussion about being commissioned as a general, his wartime leadership, or something else? Similarly, for communications, who is Washington communicating with? About what? Maybe those references would fit better under specific aspects of his life, such as his family, military experience, or presidency. 

Establishing the larger context is crucial. The context is also not always easy to identify. It can be tempting, when reading the text, to latch onto terms like “battle” or “communication” because they are easy to spot. I can fall into this trap too, especially if I’m tired, in a hurry, or having trouble understanding the text. Yet while the discussion may well involve a battle or communication, that is often not the larger significance of the passage. What really matters is Washington’s military strategy at the Yorktown siege or communications with Congress about foreign policy, for example. That context is far more interesting and specific.

To borrow a phrase from journalism, don’t bury the lede. 

Levels of Granularity

So establishing the larger context is important. But how granular, or narrowly focused, should subheadings be? The discussion may be about the Yorktown siege, but if other battles are also mentioned, does it make sense to give each battle its own subheading? Is there enough space for each battle to have its own subheading?

This is a question of finding the right level of granularity, which often depends on what the book is about. Is the book a biography covering Washington’s entire life? Or is it a history focused on a single aspects, such as his presidency? Or is the book about something else entirely, say foreign policy in the fledgling republic, and so while an important character, Washington is not the main focus. How Washington appears, and the number of references, will influence the number of subheadings, and how broad or narrow each subheading should be. 

For example, if the Yorktown siege is the only wartime mention, then that would be an appropriate subheading. If there are a handful of discussions about Washington’s wartime experience, then a broader subheading for “Revolutionary War” makes more sense. Specific details about the war will not be included in the array (though there could still be a separate main entry for the Yorktown siege), but if the war is not prominent in the book, “Revolutionary War” strikes a good balance between being specific—the reader at least knows which war—while still broad enough to gather scattered mentions. 

If, however, the book is about Washington’s wartime experience, or at least contains significant discussion spanning several pages, then a broad subheading like “Revolutionary War” is probably too broad. It would be better to create multiple, more granular subheadings for specific battles and other aspects, such as espionage, leadership, staff, strategy, etc… 

Whether broad or narrow, singular or multiple, the subheadings should try to reflect the scope and depth of the discussions in the book. 

As mentioned, space for the index can also be a factor. If space is tight, broader subheadings can still point readers in the right direction while also requiring fewer subheadings. If shortening the index is necessary, try looking for subheadings that can be combined at a broader level. 

Clarity

The third quality I look for in subheadings is clarity. The reader should clearly understand what is being referred to. For that matter, the indexer should also clearly understand. If I re-read a subheading while editing the index and I don’t know what it is about, then I can’t expect the reader to understand either. 

Clarity is intertwined with context and level of granularity. Try to be specific and concrete when selecting terms, which remains true whether the subheadings are broad or narrow. In the Washington example above, “family of,” “as landowner,” and “as president” are all clearly written. Depending on the book, they may be at an appropriate level of granularity or they may be too broad. Adjust as needed, while still aiming for clarity.

Mixing Subheading Types

It is acceptable to mix categorical and descriptive subheadings within the same array. I think the distinction is helpful for knowing which strategies to use when drafting subheadings. If the subheading is categorical, then you are likely copying the term from the text, as well as keeping an eye out for other terms within the same category. If the subheading is descriptive, you need to think more deeply about the context, level of granularity, and how to make it clear to the reader. I am not suggesting that these two types be kept separate.

That said, if there are several categorical subheadings, the array may be easier to scan if the categorical subheadings are gathered separately. For example, if several works by an author are mentioned, consider force-sorting them to the end of the array or place them in a separate, nested array. As in, “Oates, Joyce Carol” and “Oates, Joyce Carol, works by.”

Indexing Faster

Circling back to the question of speed, it helps to start with a good draft. I rarely write a perfect first draft, but if I can keep context, granularity, and clarity in mind while drafting, editing is often easier and quicker. For me, speed is mostly about learning good technique.

If I am not sure whether  a name or concept will need subheadings, I often do a keyword search to see how often the term appears. Keeping in mind that names can appear in citations and the bibliography, this can nonetheless be a quick way to gauge whether subheadings are necessary.

I also try to look for clues as to how granular subheadings should be. How prominent is the person or concept in the book? Are they discussed in a specific context or more broadly? What can I learn from the introduction or from a keyword search? While not perfect, with a little thought and research I can base my draft subheadings on an educated guess and be closer to the final draft.

Also remember that each array tells a story and needs to hold together. If the subheadings are categorical, are all relevant entries in that category present? If the subheadings are descriptive, are all relevant aspects of the person or concept reflected? Is the point made in the book conveyed? Keeping this in mind from the start and connecting to the larger context can lead to a better first draft. 

Subheadings can be tricky to write. I wish there was a shortcut, but the only shortcut I know is to understand what makes a good subheading and to practice applying those elements right from the start, to the point where good technique becomes habit. Don’t worry about trying to create a perfect first draft, as I don’t think that is possible, but the better the first draft can be, even if it takes a little more time to write, the quicker it will be to edit and the less time spent indexing overall. 

The fundamental purpose of an index is to guide readers to the relevant information that the reader is searching for. To do that, the index needs to be clearly written, which begins with the first words that the reader sees. 

Main Headings

The main heading, also known simply as the heading, kicks off the entry. This is the first word or phrase that you see in an entry and array. It is typically a noun, and should be clear and concise. If a longer phrase is needed, the main heading should lead with the most important element. The main heading should also match how the term is used in the text, such as using the same spelling and capitalization. 

The heading should be reflective of both the text and the audience. Is the book discussing cars more generally or electric vehicles specifically? Or both? Will readers be reading this book to learn about the auto industry, new innovations, or specific brands and models? Or all of the above? To give another example, biblical characters such as Matthew, Silas, and Timothy probably don’t need a gloss clarifying their identity in a work of biblical studies to clarify their identities, but these names may be more unfamiliar to readers if they appear in other disciplines. 

Another consideration is whether or not to pluralize main headings. Should it be dog or dogs? Cantaloupe or cantaloupes? To start, be mindful of differences in nuance. Freedom is somewhat different from freedoms, for example. Otherwise, I tend to follow common usage. If a term is commonly pluralized, then I go ahead and make it plural in the index, which I think reads more naturally. 

To give a few examples of main headings:

Acts (biblical book)

Cleveland, Grover

electric vehicles

heat transfer

London (ON)

trade wars, retaliatory

Subheadings

For short arrays containing a handful of locators, a main heading is usually sufficient to specify what this thing is. But more specificity is often needed for topics with extensive discussion (usually when there are more than 6-10 locators) or if there are different aspects that readers would appreciate differentiated.

The subheading is placed after the main heading. Its purpose is to further clarify what this thing is. Because subheadings often differentiate references from one another, there are usually multiple subheadings per array.

Since the subheading is appended, there is more flexibility in how it can be phrased. Depending on the context, the subheading can be either a short word or phrase, or it can be longer and more descriptive.  In all cases, the relationship between the main heading and subheading should be clear. If possible, I try to also lead with the key word, which both affects how the subheadings are alphabetically sorted and, I think, makes it easier for readers to find the subheading as they scan the array. 

For example,

Acts (biblical book): authorship; within biblical canon; commentaries on; Paul within

Cleveland, Grover: first presidency; free-silver issue; legislative achievements; private life between presidential terms; second presidency

heat transfer: conduction; convection

Effective headings and subheadings connect readers to the text. Main headings are the point at which readers encounter the index, and readers should not need to guess what this thing is. The same is true for subheadings, if the reader decides to read further into the array. 

Tell the reader what they need to know. Be specific and concise. Do this, and your index will be well on its way to being excellent.