Of course a good index is hard (read expensive) to write and so many books didn't have good indexes.
The index is so good I've shared my happiness about it several times.
Let me give you an example of a high-quality index entry from the Software Architecture in Practice (Bass et al. 2021) [1]:
Availability
analytic model space, 259
analyzing, 255–259
broker pattern, 240
calculations, 259
CAP theorem, 523
CIA approach, 147
cloud, 521
design checklist, 96–98
detect faults tactic, 87–91
general scenario, 85–86
introduction, 79–81
planning for failure, 82–85
prevent faults tactic, 94–95
recover-from-faults tactics, 91–94
summary, 98–99
tactics overview, 87
As you see, it lists a number of taxonomic terms that are merely related to each other and you might not think about Ctrl+F-ing for them unless you already want to search for them. You may come to this entry knowing about CAP and navigate away to analytic model space, 259.
[1]: https://www.goodreads.com/book/show/14786083-software-archit...
It is quite disheartening to see a comment about importance of horse shoes being downvoted. In professional blacksmith shops, horse shoeing is a job done by a qualified farrier and not as trivial as one may think. The importance of horseshoeing for horse wellbeing is also highlighted in certain key equestrian literature.
Some are. Far, far, far, far, far too many aren't.
The half-assedry of PDF creation is a major frustration.
There are scanned-in books whose index pages don't precisely match the digital pages. Good PDFs will account for that offset themselves, but manual recalculation may be necessary.
Worse are books half-assedly converted from print to digital. These often include an index (useful for all the reasons others have mentioned elsewhere in this thread), but the "faithful" reproduction of the print text means that the page enumeration in the index bears a nonconstant relationship to the digital text. The offsets are not constant.
Then there are ePubs with the above feature. The sane thing to do would be to link the index entry to occurances. Often you'll find, again, print-edition page mentions which are of little use in locating the passage within your digital edition.
One of the underlying problems is that the print notion of "page" is increasingly archaic. For languages / typographies in which paragraphs are a useful convention, paragraph numbering might be preferable (this should be constant across formats). Direct symlinks are of course useful, but these conceal information revealed in a conventional (print) index such as passages where a topic is discussed at some length, or clusters of appearances, as well as cross-references or associated references which a well-constructed index will reveal.
There's a pre-digital publishing trend of loose-leaf or removeable bindings, with publications prepared in sections or with periodic supplements, which began in the late 19th / early 20th century. Those would typically be organised and numbered by section. The concept is somewhat trite now, but I think of it as a significant stage and evolution of publishing, somewhere between fixed-format codices, periodicals, and eventually databases and wikis.
Sure, there's a lot of efficiency to Ctrl-F a text string and just find all the places in a document. I won't deny that it takes me longer to pull up the index, search for the function name in the index, then flip to the page. But then I can just leave the book open at that page on the desk (or my lap). I never have to Alt-Tab, or fiddle with the location of windows to switch between looking at documentation and looking at the code I'm working on.
This difference was more stark when I was trying to close-read a different specification to ensure that I understood it well enough to make sure a PR implemented it correctly. I needed to have three different parts of the specification open simultaneously to bounce between all of them. With physical paper, that's just a swish of a hand away. With a PDF reader, well, goto that other section, scroll down to the piece I wanted, now goto the first section again and scroll down again and wait what was that back thing again goto and scroll and scroll and goto and descent into insanity. Trying to use multiple windows ameliorates the problem somewhat, but it also takes an inordinate amount of time to set the view up correctly, and I often end up running into the "focus doesn't follow the eye gaze" problem of typing in the wrong window and ruining the view.
I pretty much just use screenshots in snagit for that stuff.
I grew up with that and it's a very comfortable skill set.
On the other hand, I've learned ways to manage and reference information in digital formats. Bookmarks and links and pasted snippets. Attachments and full text search. Not to even get into real sicko stuff like Notion and Obsidian and DEVONthink.
Being able to easily flip back and forth between pages is a very useful technique, but so is being able to snap a screenshot of a pdf and keep it open it in another window.
I'm a sucker for paper but I'm resistant to the idea that all of these things are irreplaceable
This, I'm really comfortable with technology, but I feel like a boomer when I watch kids that have grown up with it their entire lives. Some people don't need the ability to cross reference things much, but folks who do develop the skills the need without having to revert to printed material.
The real problem seems to be licensing. Lots of books are physical-only, and the digital versions are those annoying "epub" files instead of PDFs.
Epubs can be reflowed to fit any screen. If done properly at least. For PDFs you basically need an A4/letter screen to read them comfortably.
PDF's work well for a sufficiently large e-book reader. Full-sized isn't essential, though I find the 13.3" display I use is quite pleasant to read --- roughly equivalent to a large iMac Retina display for reading ease (less overall real estate, but more comfortable to hold in one's hands, and of course, read under bright light / direct sunlight), and vastly superior to a typical smartphone.
Smaller displays of 8--10" should work in most cases and are far more affordable. The exceptions are typically scans from print, especially of small-font and tightly-rendered journal articles, or works with extensive graphics and diagrams. Those with young eyes can probably manage better than the olds.
ePub fits any sized display, but there are times when fixed layout truly is preferable for reading, context, understanding, and juxtaposition of text and graphics, etc. With a fixed layout and a competent layout engine or editor this can be optimised. With a flexible layout* (HTML, ePub, etc.) the dynamic element pretty much always leads to compromises or gaffes in layout and positioning.
Fixed-layout also means that spatial memory of where within a document, chapter, and/or page specific elements / contents are. Dynamic layout greatly reduces the ability of those who have strong spatial memory of written materials.
I tend to prefer LaTeX or a similar doc-prep system myself for authoring.
Only because you prefer to work that way, someone that has grown up with everything digital has equivalent skills doing that stuff using tabs, digital sticky notes, bookmarks, and such.
So I use mostly digital material and most of the books stay at home for studying (the books are heavy).
You can't do it quickly. Jumping between random pages isn't useful (and not faster than in an ebook), so you want to jump to a specific page, and here ebook is much faster, whether you're opening a page number or a page with some content you remember
> know where to flip to approximately to start my search.
Or you can start precisely with an ebook
And then your highlights also can't unstick because there is some dirt that ruined the stickiness of a note. And your carefully prepared unsticky bookmarks (you didn't have sticky notes around, so you've followed your advice and improvised) can't all fall out just because your book fell with its back up
But there are reasonable affordances to a practical extent within both formats.
I have a large print collection, and a much larger digital one, presently largely on an Onyx BOOX ebook reader. I'm well acquainted with the capabilities and limitations on both systems.
(I've discussed the BOOX device fairly extensively in previous HN comments for those interested.)
<https://cool.culturalheritage.org/don/dt/dt3508.html>
<https://en.wikipedia.org/wiki/Thumb_index>
Image: <https://en.wikipedia.org/wiki/Thumb_index#/media/File:Blacks...>
Those may be cut in, or self-applied as with index tabs:
The entire notion of a tabbed interface in the computer sense derives from index tabs:
Besides, these are impossible to implement for anything dynamic, so they aren't even useful at all in most of the cases
If you're referencing between two or more sections of a book, bookmarks, index cards, stickies, tabs, etc., are all there for you.
Source: old school printed book research.