Mdthbs

I find it hard to write the literature review while I have Google, the Internet, and all free very easy to search for information tools.
I have to search for days to find a piece of information that related to my research.
I really would not be able to do that without the Internet and the technology help.

This really makes me wonder how people in the past did that:

• Did they have to read the entire book to find a piece of information?
  I know they might have used the index, but still this wouldn’t have given them the details of what they were looking for.




• Does that mean people in the past (before the Internet) worked harder to achieve their degrees?




• Does that mean that research before relied less on references?

We depended on libraries and librarians. Grad students would spend hours in, say, the math section of a good academic library, going from book to book and taking copious notes (on paper, of course).

But, often enough, the next paper we needed to look at wasn't in that library at all, so you would go to the librarian and ask for a loan of the resource from another library.

But it was also an important technique to use the librarian as a 'knowledge expert' who could, and would, suggest things for you to look at and places to look. I don't know if librarians still get the training to do that.

And, of course, you could ask your colleagues for hints about which rocks to uncover to find the gems.

(Comment extended to post:)

My impression is that part of the answer is "they didn't", or more precisely "they were only as good at it as their own knowledge and that of their communities". In particular, at least anecdotally, many things in mathematics were discovered in parallel for lack of easy communication and inter-visibility. [This is complementary to @Buffy's answer, which explains why people found anything at all.]

I have tried to put this on solid footing by comparing numbers of references in a 1970 issue of a mathematical journal vs. in a 2019 issue of the same journal. This turned out to be surprisingly nontrivial. Firstly, it's not clear if I am comparing apples to apples, since most journals have changed their publication criteria and sometimes even their (implicit) subject within these 49 years. Secondly, papers in almost every part of mathematics have gotten much longer (by a factor of 2.8 in my sample). Thirdly, empirically, Project Euclid bans your IP if you load more than about 20 PDFs in rapid succession, and Sci-Hub is slow and has captchas. There might be a way to do such research using MathSciNet, but I am nowhere near proficient enough at its use.

So I ended up comparing Proceedings of the AMS (due to their long back-catalog of freely accessible issues), and came up with this ("reference" means "bibliography item", not "place where a bibliography item is being cited"):

I picked 13 of the papers from Proc. AMS 141 (2019) #12 (more or less picking the first 13, except I skipped a few from the Abhyankar cluster since he writes and cites in rather idiosyncratic ways). The average paper has 1.5 references per page:

I picked 13 of the papers from Proc. AMS 24 (1970) #1. The average paper has 1.2 references per page:

Should we really compare references per page? There are good reasons to assume that the number of references per page should decrease as papers get longer, since the references cited in Section 1 won't normally be disjoint from the references cited in Section 2. As a consequence, the discrepancy between the above numbers looks even starker.

I can only explain this discrepancy in two ways:

1. the literature has grown much larger, and not just by the addition of new disciplines but also by more people writing about the same discipline;




2. (as the OP observed) finding relevant references in the literature has gotten easier thanks to the Internet, Google Scholar, etc.

I don't know how to properly disentangle these two causes.

It was a LOT harder before the internet. Time traveling to and from the information source is eliminated by instant transmission of data. If people were lucky enough to be able to spend long stretches of time in a library, the amount of information they could find was, for those days, a "lot." There were these things called "card catalogs." They were furniture, basically, in which long, little drawers were kept, and the drawers were organized by subject, and inside each drawer were hundreds of little cards, and you'd find information about one individual book on each of these cards and determine if you wanted to go walk sometimes long distances and up elevators or stairs to "the stacks" (where the books were) to find this particular book or not. (Google Dewey Decimal System.) You'd write down the ID info about all these books onto what would often become long lists. Then you'd go to another part of the library, where the books were ("the stacks") and pull books, many of them hardbound, off of shelves. Lots and lots of books sometimes. Yes, they'd actually read "the whole book"!!! (Couldn't help but laugh hard at that question.) And sometimes not. And they'd underline sections in pencil (and ink, unfortunately), and place books face down with pages open to pages they needed to look at as their hands went to and from the typewriter, and they'd put bookmarks in between pages in an effort to be able to go back to references and material they wanted to put into the project they were working on, as they attempted to create an effective structure without Select, Copy, Cut, Paste. If they couldn't type, they'd write it out by hand on pads of paper, and cut paragraphs and sentences with scissors (I"m not making this up) out of one section so they could rearrange the sequence of their text by taping it and gluing it to other cut-up pieces. (Google the word "mucilage.") Before this stuff called WhiteOut was invented (by a mom, apparently, with stuff in her kitchen), typists had no way to correct an error on a page; they'd have to start the entire page over again. The invention of the IBM Selectric typewriter was revolutionary and a gift from heaven because you could correct backwardsly about 12 spaces. You could check books out with a library card, and you had to return them usually within two weeks or pay a small fine. And if you didn't return the book, you had to pay for the book. (One of the many good things that broke down in the social decay of the last few decades was that people started stealing books from libraries, something nobody ever did before.) Some libraries had little tiny rooms (e.g. New York City) that they'd let serious researchers use privately for months. And they could get "a lot" (by the standards of the day) done. But it was a small fraction of what you can get done now. Someday, when you're in your 60s or so, a young person is going to ask a question that will make you laugh because you can't believe things have changed so much that young people don't know what something used to be like. It was a LOT, LOT, LOT harder to get a degree, build a business, make almost anything... than it is now. I mean A LOT LOT HARDER.

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Although I haven't really known this time myself, I think it's important to mention the much more crucial role that conferences and journals used to play in the dissemination of specialized knowledge. A researcher would usually try to attend the conferences of their field and get their local library to subscribe to the relevant journals in order to keep up to date with what people are doing in their research community.

At the time researchers would preciously keep these massive conference proceedings whenever they attend a conference. I know a few senior researchers who still have their offices shelves full of old proceedings and journal issues. In order to keep up one had to follow the series of conferences/journals relevant to their field, but it was feasible because there were not as many publications (and publication venues) as nowadays. They didn't have to read the entire volume but at least they would read the most important publications and make a note of potentially relevant ones. To some extent they relied less on references indeed, and they relied more on the reputation of a journal or conference to cover the recent progress of the field.

The question of whether they worked harder is subjective. The nature of bibliographical work was different and certainly more time-consuming, but researchers were not expected to process more than what is humanly possible: overall the research system was proportionate to the technical constraints. Like for many things, I think that people used to make more out of fewer resources: exploiting the resources they had access to in a deeper and more extensive way, whereas nowadays we often can only afford to skim through the massive amount of literature... I could keep rambling about disposable research but that would be very subjective and out of topic ;)