One of the professors for my MSc in Computer Science told me that students should not read textbooks that have more than (around) 250 pages during the 4-month semesters of coursework. The reason is, according to him, that a 4-month semester is a limited time to study and successfully pass all the courses. Trying to read big/heavy textbooks is nothing but a waste of time, and it reduces the chance of getting good grades.

Have you ever heard about this theory before? Is this theory very popular at your university?

  • 33
    I am wondering if 249 pages books are OK...
    – Nick S
    Dec 20, 2020 at 0:08
  • 4
    @NickS: Even 250-page books are okay according to the criterion here.
    – user21820
    Dec 20, 2020 at 3:07
  • 5
    i have seen book with 1000 pages that contain no more information than 100 pages...
    – lalala
    Dec 20, 2020 at 9:10
  • 2
    Time is not something that is produced, so it's unclear to me how something can be counterproductive with regard to time. The question for me is what you want to achieve with the knowledge from the book. Dec 20, 2020 at 19:19
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    Ah yes I forgot that the point of uni is to get good grades, not to learn new things under the guidance of experts in the field. Dec 21, 2020 at 10:17

7 Answers 7


It comes down to whether you want to learn more things or to pass the course (note they are not synonymous).

  • If the first, then no, it's not counter-productive. You will learn more by reading the textbook, almost by definition.

  • If it's the second however, then yes, it's counter-productive. It's the material covered in the course that will actually end up on the exam. Accordingly you want to study that material and that material only. Any time spent on things that aren't in the lectures is time wasted, and chances are when you read these supplemental textbooks, much (or even most) of the material will not be covered.

Unless you spend significantly more time on the course, viewed another way, these two choices basically come down to "do you want to know more things" vs. "do you want to master a few things". It's not obvious which is better.

Finally, do note that although the first option might sound better, in practice it's usually the 2nd that matters - in a job interview or PhD application, the grades on your transcript are important, and if those are poor you will often not get the chance to demonstrate that you know more than the grades indicate.


I haven't heard of such a thing, but can understand where it comes from. But my advice would be that doing teaches you much more than reading. In CS we often build things to reinforce learning. Textbooks can provide useful exercises. And one learns, primarily, through repetition (reinforcement) and feedback. Only a few people have a "photographic memory" and even then, being able to recall some text doesn't mean that you have gained insight from it.

Seek insight. Reinforcement and feedback. Hopefully the professor provides feedback, but programs (when they fail) can also do that.

I don't think the professor means to ignore textbooks, however. Use them "just enough" to gain insight.

  • But my advice would be that doing teaches you much more than reading. And teaching does more than the two combined. I always understood a topic much better when I actually had to explain it to someone. Take yesterday - I was explaining to my son (high school) the concept of "field" in physics. While it is something I got used to, I found it enlightening to teach it to someone in high school (I taught at universities so it was more formal/mathematical than in high school). This also helps to reconsider a thing or two in what you think you know.
    – WoJ
    Dec 22, 2020 at 16:12
  • @WoJ, yes, having to explain something is often the key that opens the door. It is one reason I favor pairing in most student work. Even when the students are mismatched in "skill". The one doing the explaining learns as much as the one listening.
    – Buffy
    Dec 22, 2020 at 16:16

That's ridiculous advice. Believe it or not, lots of thick assigned textbooks contain useful information that's not covered in lecture.

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    – Massimo Ortolano
    Dec 22, 2020 at 8:31

You shouldn't base your learning style on what one professor said once in a lecture.

There is a variety of reasons he could have said that:

  • He is not against textbook as a means of studying per se, but wants to direct his students towards the shorter and more efficient textbooks rather than the long and inefficient ones (most likely)
  • It's personal: The professor himself once read a long textbook on the topic, but realized that he's wasted his time (doesn't mean this will apply to you!)
  • There is a notorious book specific to your field that students typically pick up. Unfortunately, it is not a good one.
  • He's had a bad day and made a thoughtless remark (professors are humans too)

By the way, you don't need to read a textbook cover to cover. Even if it has >1000 pages, pick out the things relevant to your studies. However, it is unwise to claim that textbooks are not a good way to learn.


I agree with most of the answers that this is silly advice, and have not heard it before, but one key point not explicitly mentioned so far is:

Most textbooks are not written to covered in their entirety in one semester.

Some are meant for a 2-semester course and some intentionally have more information so instructors can pick and choose what they want for their course. Also some instructors move faster than others.

I remember thinking my Algorithms book (Cormen-Leiserson-Rivest, still on my shelf 20+ years later) was very well-written and useful. It's about 1000 pages and of course we didn't cover everything in 1 semester, but I certainly learned quite a bit from reading the parts we did cover, and possibly other sections I was interested in that we didn't get to.


As a blanket recommendation, this is fairly obviously silly.

For one thing, "textbook" is very ambiguous. Some are full of make-work crap. Some have lots of useful information. Some are badly written (making it difficult to glean information), some are well-written, making it easy to see the point of the discussion.

There are popular slogans about "just doing exercises" and so on... I'd certainly agree that it is essential to engage, but, also, it would be pathetic to fail to learn from all the smart people who've already thought about things. Some of their conclusions and solutions are exactly what are in texts. And should we be confident that all of those good ideas fit into a little pamphlet, rather than a 250-page book?


I would generally agree that reading textbooks has limited uses and poor returns on investment of time. The only cases where I have found this not to be true is when a) the text book is short and focused or b) the textbook is the basis for exams. But other than that, it is very rarely the case that all the knowledge contained in a long textbook is useful and that reading it front-to-back is the best way of acquiring that knowledge.

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