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I never really understood the point of having a course with lectures when the course has a textbook. Sometimes the subject is so high-level or specialized or so modern that the contents are changing rapidly that there is no textbook (for example at the graduate level). But more often the textbook includes everything that will be said in the lecture, and much more: extra content, exercises, answers to exercises, appendices, etc.

I assume a STEM context, that is we can assume the textbook is available in the sense that there is one comprehensive source that contains undisputed facts, as opposed to a broad literature with lots of interpretations and opinions (as may be the case in non-STEM contexts).

So what is the point of a lecture?

Raphael
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math_lover
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    For some people in some classes, the lecture is pointless. But there are people who do better in class, or people who are not disciplined enough to read the book themselves; and there are classes where a great deal of value is added over the book. – ff524 Sep 02 '15 at 21:15
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    The textbook and the lectures should compliment each other. One should not be a replacement or substitute for the other. – Raydot Sep 02 '15 at 21:18
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    A lecture gives you a formal setting. Otherwise, why go to school? You might as well self-learn, take an exam when you're ready and collect your degree. Also, a great lecturer/teacher will not 'read' from textbook and tell you the fundamentals that govern everything. Also he/she may teach you how to 'think' about a subject/topic. Lastly, there has been research that says you absorb more when someone tells you the info versus you reading the same info by yourself. – Prof. Santa Claus Sep 02 '15 at 22:04
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    "Why go to school? You might as well self-learn, take an exam when you're ready and collect your degree." That is a very good question which I am not sure how to answer either... – math_lover Sep 02 '15 at 22:28
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    You can ask questions in a lecture. – Felipe Voloch Sep 02 '15 at 22:31
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    You can also do this at office hours. – math_lover Sep 02 '15 at 22:49
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    @ff524: Learning styles are a myth. See Pashler et al., "Learning Styles: Concepts and Evidence," http://psi.sagepub.com/content/9/3/105.abstract . Their review of the literature finds no support for matching instruction to learning styles. See also the two links given in EnergyNumbers' comment. –  Sep 03 '15 at 00:08
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    @JoshuaBenabou Asking questions at office hours is pretty ineffective if 200 other students have the same question. – Sumyrda - remember Monica Sep 03 '15 at 01:54
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    My point is you don't need a lecturer to repeat information in the textbook for you to ask a question. If the instructor thinks the question is a common one he will bring it to the attention of everyone at office hours, for example. – math_lover Sep 03 '15 at 01:57
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    Have any of you heard of people teaching themselves from books and then testing out of math classes at the undergrad level? – Paul Proteus Sep 03 '15 at 01:59
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    Also, the answer to this question is very different for STEM vs. non-STEM. In STEM, esp. in math, often the lecturer basically repeats the proofs from the book verbatim. In history, for example, it is really important to have a human teaching you, because each book has its own, possibly narrow, perspective, and in any case one can't read every history book on every subject; the lecturer needs to create a course consisting of the important subset. – Paul Proteus Sep 03 '15 at 02:01
  • @ReneG: yes, this is not uncommon. Also I had in mind STEM. – math_lover Sep 03 '15 at 02:10
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    In my experience, a great many lectures have served only as means to gather participation points. –  Sep 03 '15 at 03:08
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    What is the point of seeing a play when you have the script? – Calvin's Hobbies Sep 03 '15 at 06:00
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    Ideally the lecture is not just a rehearsal of the book. Most university level subjects are not just "oh, i read it twice and will understand everything" kind of material, therefore an active quittance, pointing out common pitfalls, external feedback by tests etc are rather necessary. – Greg Sep 03 '15 at 06:33
  • @BenCrowell I would take that "study" with a huge grain of salt - might be worth reading an article about psychology studies in general: http://www.theguardian.com/commentisfree/2015/aug/28/psychology-experiments-failing-replication-test-findings-science Also, from personal experience (Maths) I have a huge preference for a handwritten lecture over pre-prepared slides - and yes, one subject switched, so I experience both on the same subject. – DetlevCM Sep 03 '15 at 08:21
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    @BenCrowell: That paper doesn't show learning styles are a myth - that's a much stronger claim than it's making. They are basically saying nobody has created a successful programme using learning-styles assessments to enhance learning outcomes and proved it, i.e. there's a lack of good evidence, not even that there's evidence of lack of success. – psmears Sep 03 '15 at 09:41
  • There's a great talk about this. Which I think makes a lot of sence. Have student watch lecture at home (video of the best teachers, or read the book) and do "homework" in the classroom. I remember, the time I had to most question was when doing the actual work. – the_lotus Sep 03 '15 at 11:13
  • Please take extended discussion to [chat]. – eykanal Sep 03 '15 at 12:33
  • @Calvin'sHobbies I wouldn't say most lectures, especially at the graduate level, are really works of art. – user8001 Sep 03 '15 at 20:42
  • Here is clearly the answer you want: None, there is no point. – pjs36 Sep 04 '15 at 01:18
  • @above: I don't appreciate that. I already had some ideas on this topic but I have come here to ask my question because I am open to other ideas. I don't want an answer with no explanation. – math_lover Sep 04 '15 at 01:31
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    @Calvin'sHobbies: Thank you for sparing me the need to invoke an analogy concerning a woman and a dirty magazine. – dotancohen Sep 04 '15 at 06:48
  • Answers to this similar (but not identical) question might also be interesting to you: http://academia.stackexchange.com/questions/29805/why-have-lectures-in-the-information-age – ping Sep 04 '15 at 17:21
  • @CreationEdge Lectures serve an important purpose. They allow students to nap mid-day. Sleep is medically necessary. – emory Sep 05 '15 at 01:07
  • @the_lotus. Oh, so something's going to revolutionise education again, is it? – TRiG Sep 05 '15 at 03:30
  • @TRiG isn't your video saying the exact same thing as the one I posted? – the_lotus Sep 05 '15 at 18:00
  • As the question is now protected I will need to answer here. The job of a good lecturer is to expand and illuminate the material presented in the course texts as well as allow the presentation of extra insights into the subject. Linked with tutorials this allows a good student to validate their understanding and seek clarification of any ambiguities . A lecturer who slavishly repeats the text book is not earning their salary and is not giving the students the education they are entitled to – Stevetech Sep 05 '15 at 20:33
  • Going through problems seems to be the most illuminating way to gather new insights. Wouldn't you agree that doing problem sets, especially in collaboration with others, is better for learning than attending a lecture. – math_lover Sep 05 '15 at 21:21
  • In my experience, I remember a lot better the things that I hear than I do the things that I read. It will take me a lot longer to take in information when reading it, as I may need to reread several times to really appreciate it, whilst listening in a lecture I can take it in immediately. I read no books and barely read any course notes at university and still got a First Class Degree. Lectures were invaluable to me. – Luke Sep 07 '15 at 09:50
  • Just my personal experience: I have never found lectures which follow textbooks exactly to be useful. Maybe some Q&A, but that is usually stuff that I can't answer simply in class without slowing the class down, so I defer those questions either to office hours or in an e-mail. I'm having quite a different experience currently with professors who don't follow the textbook at all at a new university, and I feel that my understanding of the textbook seems to be paying off more than merely reading the textbook to find out what I'm going to hear about during a lecture. – Clarinetist Sep 08 '15 at 03:13

22 Answers22

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I started writing a post about all the things I like to do that the book doesn't: offer an intuitive overview, a fresh perspective on the basics, etc.

Then I realized that of course, there's no reason that the book couldn't do these things. Most of them don't, but there's no fundamental reason not to. Everything I do in a lecture to help students see the subject from all sides could be translated to the book.

So I guess the main point of lectures is just that it's another medium. Yes you could learn from only one medium, but it goes faster if you use multiple media at the same time. Not just books and lectures: websites, games, audiobooks, documentaries, programming, role playing. Each medium has it's own slight advantages, and idiosyncracies. Even if the story is the same, the energy you have to put in, the mixture of senses you use, and the parts of your brain you activate are all different.

So what, specifically, are the benefits of the medium of a lecture? Here's what I can think of:

  • Obligation: You are expected to be there. It may be childish, but for a lot of students, it's difficult to work if someone isn't making them do it.
  • Interaction: It's not just that students are able to ask questions: lecturers can ask te audience a question too. And even if you're not the one answering, you're definitely checking in your head whether you know the answer, which means you're interacting with the material. A book can do this too, ask a reader to consider a question: but the sense of stress isn't there.
  • Intonation, rhythm and storytelling: A good speaker can hold the attention of an audience. If you're reading, you have to do all the work to keep the attention. The author simply has fewer tools to keep you interested.
  • Presence The fact that there's an actual person present in the same room as you, makes you sit up. This is a simple human convention. As most lecturers know, it's a convention that students find easy to dismiss, but the basic sense that you're in a room with another person still changes the energy.
  • Speaker guidance A good speaker will sense the energy of the room. This lets her change speed, take a break, or spend a bit longer on a subject if she notices the room isn't following along. This makes each lecture tailored to the audience. The smaller the audience, the more different the lecture from audience to audience.

Of course, it takes a special lecturer to understand these points and try to capitalize on them. Many don't and just follow the book.

Peter Bloem
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  • While I have appreciated lectures for the reasons you list (rarely all of them in the same classroom, unfortunately), I feel like this answer succumbs to the false dichotomy "lecture vs self-learning" underlying the question and many answers. Ben Crowell's answer shows that there are alternatives. – Raphael Sep 03 '15 at 08:55
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    @Raphael that's not at all my intention with this answer. As I said: if you want to learn something, try to get the material in as many different forms as possible. A lecture is one, and sitting down with a book is another. In fact I'd say the lectures are optional and the book isn't if you really want to learn something. I'm just trying to answer the question of what the specific value is that lectures offer over other media. – Peter Bloem Sep 03 '15 at 11:39
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    Education is a relationship and it's a lot harder to have a relationship with an author via a book than with a lecturer via being able to discuss things face-to-face. I think your answer captures that concept. +1 – Todd Wilcox Sep 03 '15 at 12:34
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    I like lectures because it highlights what the teacher feels important. You can get a lot of meta-data by watching what they place emphasis on. Plus, as always, you might learn from the other students' questions or general tangents and stuff. – gloomy.penguin Sep 03 '15 at 17:33
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    @above: the lecturer could just share his lecture notes with students... often lecturers refuse to do this, which doesn't make sense to me. A classroom full of 50 students or so all copying the same thing, which is already written down somewhere, baffles me. – math_lover Sep 03 '15 at 23:24
  • "The fact that there's an actual person present in the same room as you, makes you sit up." We are still talking about students right? – Joseph Sep 04 '15 at 12:14
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    @Jospeh, I know, I know :) Still, I like to think that you get at least 5 or 10 minutes of courtesy attention before they open their laptop and start playing minecraft. – Peter Bloem Sep 04 '15 at 12:17
  • @Peter - Haha that's true =) – Joseph Sep 04 '15 at 12:32
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    With a text book you are required to sort everything out for yourself.

    By having access to an expert (the lecturer) there is the potential that you can learn more efficiently. In general the expert is knowledgeable not only about the topic at hand but at associated issues including prioritizing topics and tricky concepts that need better or further explanation. By attending a lecture you can tap into the expertise of the lecturer like your own (more or less) personal guide to the topic at hand.

     – user3730788 Sep 04 '15 at 12:49
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    @JoshuaBenabou the rationale behind not handing out lecture notes is that the professor actually wants people to turn up for the lecture and they feel there is very little insensitive for people to show up when they think they have everything they need. One of the best lecturers I know does this, and it is because most undergrads and some grad students don't have the maturity to appreciate the additional benefit they are actually getting from the lecture. Also there are studies that show the act of taking notes reinforces the process of forming memories. – AMR Sep 04 '15 at 14:55
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    @JoshuaBenabou In addition to what AMR wrote, a good lecture is also a performance, for which the notes are more like a script. I furthermore agree that there should never be a classroom of any size copying the same thing. Each student should be making their own notes in their own words, because the mental processing necessary to do that is an essential part of learning, and arguably the entire point of both lectures and homework. Teachers handing out lecture notes are actually doing their students a huge disservice. – Todd Wilcox Sep 04 '15 at 17:06
  • Well handing out the lectures for students to read is the same thing as reading a textbook, no? – math_lover Sep 04 '15 at 19:54
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    Research shows that students who skip lectures do the same at their exams as those who attend. Can you provide references? I vaguely remember studies showing the opposite (at least in math), but the question of causation vs correlation was unanswered. – Kimball Sep 05 '15 at 11:42
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    @Kimball I'm afraid I was a little sloppy there. Our department director always says this. And while I'm sure she has good research to back this up, I can't find it myself. What I can find is several studies suggesting the opposite. I'm not if the question has been definitively answered yet, but what I said was definitely wrong. I removed the paragraph. – Peter Bloem Sep 05 '15 at 13:38
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Let me give you an answer in the form of an analogy.

Say you head to a city in a foreign country where you do not know the language, have no friends, do not have a guide book, maybe just have a map, but most of the words are the local names, and you do not have an idea of what they all mean.

Now you could look at that map and resolve to follow every single street until you have walked the entire city. You could even make notes on the map of every place of interest, but that will take you a long time, and a lot of effort. A large majority of the streets that you walk down will hold no interest for you and some of them may look like they lead somewhere, but due to construction have become dead ends.

Now let's say instead that you go to the same city but you hire a local guide that is very fluent in your language, or it could even be a friend that lived there for several years. With a few questions they will likely be able to figure out your interests, what you will find fascinating and what will just waste your time. They may even know of some hidden gems that, in the prior example, you got to towards the end of a day when you were totally exhausted, and you just didn't notice them, so you missed out.

Well, even an average lecturer, especially one that is actively involved in research in that field will be that tour guide in that subject. You will be more productive, you will learn more of the relevant information, and will allow you to skip the 300 pages of filler material that the publisher made the authors include to justify the $200 price tag on a new edition to a text whose prior edition was only two years before.

A great lecturer will get you to see how all of those facts are actually linked together in a consistent and coherent whole and will start you thinking about the material as an expert would. They can provide you with insights that will refocus the material and let you see it with new eyes. They can make you think about ideas and draw conclusions that you may never come to on your own...

That and they also give hints about what they feel is important and what is going to be on the exams. Also, if you need a letter of recommendation, the authors of the book aren't going to write it for you and the clerk at the campus bookstore isn't going to carry very much credibility. So prep by skimming before lecture, read in detail after lecture, but most importantly, get yourself into a seat in that lecture hall and maybe make the additional effort of heading to their office hours as well.

AMR
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    Yes, exactly this. The main purpose in my mind is that the professor can provide guidance on what is important and what isn't. Even the worst professors aren't going to stand at the lectern and read every word of every chapter - they will need to cut out the extras and the tangents to only provide the key points of each lesson. – David K Sep 03 '15 at 13:17
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    You don't know what worst professors do, do you? :) – Ketan Sep 04 '15 at 18:28
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    Let me put it to you this way @Ketan; even the worst professors have more experience that you do if you are not a peer or a colleague. If you are a student of life, then there is always something you can learn from someone else, even if it is how not to do something. – AMR Sep 05 '15 at 04:20
  • @AMR I understand. My comment was just a spontaneous blurb. – Ketan Sep 05 '15 at 15:33
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What is the point of a lecture when you have a textbook?

If "lecture" means the professor presenting material while students sit in their seats and take notes, then for a great many subjects, the evidence is that there is no point. See, for example, Freeman et al., "Active learning increases student performance in science, engineering, and mathematics," http://www.pnas.org/content/early/2014/05/08/1319030111 . This is a meta-analysis of the effectiveness of active learning compared to lecturing. Active learning is significantly better, at the 95% confidence level, in essentially all STEM fields, as measured by success rate or normalized gain.

Lecturing originated in the middle ages, when books were so expensive that it was impossible for students to buy them. Students would listen to a professor read the book out loud, and they would copy down the contents of the book, so that they could have their own copy.

Today, lecturing continues to exist for a variety of reasons. It's a cheap way for a university to offer a course to 300 students. Students also tend to like lecturing because they can be passive rather than being put on the spot and asked to do something.

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    This. It's not about lecture vs self-learning, it's about models how we spend time with our teachers, and if classical lectures are a good one. Another useful buzzword to Google with is flipped teaching/classroom. – Raphael Sep 03 '15 at 08:51
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    Umm, many (if not most) students would not pursue active learning vigorously if there were no lectures. Many would not pursue it at all, except right before exams. – einpoklum Sep 03 '15 at 16:01
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    Why? Weekly problems sets which are to be discussed in class would provide a schedule for students. – math_lover Sep 03 '15 at 19:55
  • Someone finally mentioned the actual research, pedagogy is changing, and lecturing has been shown to have little utility, class time really should be used to do "active" learning, also called learner centered teaching. – daaxix Sep 03 '15 at 23:11
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    @einpoklum Then they'd fail, and that is as it should be. – Raphael Sep 07 '15 at 09:55
  • @Raphael: If only that were true. Many universities, and academic staff, do not like mass failures. In fact, in my alma mater it is often ensured technically that grades average out at about 70, almost regardless of what actually happened. On the other hand, failure is considered a horrendous outcome, something to be quite ashamed of. If the culture were different, I'd agree without reservation. – einpoklum Sep 07 '15 at 11:26
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    @einpoklum I hope we can agree that those are incredibly harmful policies. Placing customer satisfaction above skill certification as a priority and designing and grading exams is a poor choice that does not lead to (only) qualified graduates. A system where such priorities are in place is broken and, frankly, makes discussing didactics obsolete (since the learning outcome is irrelevant). – Raphael Sep 07 '15 at 13:55
  • Comments are not for extended discussion; this conversation has been moved to chat. – ff524 Sep 09 '15 at 00:33
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The other answers address important aspects of this meaningful, elephant-in-the-room question. But, yes, the ideal, that you can ask questions, that something more than the mere text is conveyed, is not reliably met. Yes, very-good lecturers "add value", but this is not so common, in my field, mathematics. Sure, there's the human element, the reiteration, but if a student/learner has the modicum of self-discipline to read (several) books, there's scant reason to go and sit in a hard chair in a too-cold or too-warm room at randomly-chosen moments. I think only exceptionally gifted experts, or exceptionally gifted teachers, make going to class worth-while for a highly-motivated learner.

The "problem" is that most students cannot accurately identify their own state, their learning "tendencies", and so on. So their appraisal of "lectures", or, probably any classes at all, are not reliable, even for their own best interest.

E.g., even the "just read the book", as objectifiable as it might seem, depends on "the book" being up-front about underlying assumptions, for example. Yet there is a nearly-universal conceit in math texts that there is no context, nothing implicit, ... everything is absolute. And some of the absolutes are not acknowledged, either.

So, yes, self-learning by reading can be made difficult by the secret obstacles... but/and in-class learning can be made difficult by the very same things, merely said out loud and in a ponderous voice by unhelpful instructors.

So, yes, often, one can learn more from browsing around libraries/internets than from going to class. But it requires more effort, in fact. So, yes, many "classes" are not of value, maybe even negative net value if they interrupt more productive thinking, or, ... sleep.

Depends, yes.

paul garrett
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  • Is this just a verbose way of saying, "lectures help some people"? – Raphael Sep 03 '15 at 08:55
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    It's possible that most of my lecturers were "exceptionally gifted experts" (some of them were senior professors and my university is well-regarded), but personally during my mathematics degree I found that seeing people actually work through the material at a semi-plausible pace was a great help compared with static and highly-prepared text. In a textbook you don't see someone at the top of their field go "oh!" and look back through their work to find and correct a mistake! Of course there are other ways than lectures to experience this and it's not impossible to learn mathematics without it. – Steve Jessop Sep 03 '15 at 09:42
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    I wonder if I went to an excellent university for mathematics and never knew it until now, since all of my math lecturers added a lot of value. Certainly attempting to work through Baby Rudin without the lectures seems like a route to madness. – Todd Wilcox Sep 03 '15 at 12:36
  • It's been my experience during my education in engineering, both undergraduate and graduate, that the development of ideas often takes huge leaps that a person not already familiar with the material will find impossible to follow. Most of the lectures in my classes detailed those developments in ways that were easier to understand (I say most because some profs were horrible lecturers). Or the professor would demonstrate 3 or 4 different paths to the same answer vs. the 1 in the book. – DLS3141 Sep 03 '15 at 14:09
  • On the other hand, one of my best classes was Heat Exchanger Design, a graduate level class that dealt with fun stuff like mixed phase flows. I was the only student and the prof just told me what book to get, gave me the homework assignments and said, "Come see me if you have any questions or when you're done so you can start the projects." The projects were the same way and the exams were all of the open book, take home variety. I talked to him maybe once a week for the whole term. – DLS3141 Sep 03 '15 at 14:18
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Questions of this nature keep occurring through the history of education. You have suggested that with books we do not need classes; yet we have had books for the masses for quite some considerable time and we still have schools, we still have universities and we still have classes.

One Hundred years ago the role of Books themselves were controversial and some felt that they would be replaced by the movies, and then television and then the internet, and then ....

Yet people still go to class and we still teach.

Its because being an autodidact is rare. However if one is lucky enough to be an autodidact then one can manage without the lecture, without the class, without the university. But then you'd be one of the few.

But what if we could teach you something? How would you ever find out if you only use the book, the movie, the internet, the phone, .....

To quote one of my students: "You really know something don't you? You know? You really, really know stuff..." Up until that point there was a belief that we just read it out of a book.

Some of us do "Really, Really know stuff..." and some come and find out what it is.

Brian Tompsett - 汤莱恩
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  • It seems to me that anyone with above average intelligence who is very motivated to study the subject in question can absorb the information in a book in the same way they can listen to the information in their ears. – math_lover Sep 03 '15 at 02:04
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    @JoshuaBenabou What proportion of students do you think are 'very motivated'? – Jessica B Sep 03 '15 at 07:03
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    A small proprotion, but most likely if one is not very motivated one will fail in the long run anyway. – math_lover Sep 03 '15 at 11:46
  • @JoshuaBenabou I wish I could upvote that comment more. If somebody just goes to school/university because they're made to, then it's rare they would do anything worthy of note. Chimpanzees would be as easy to train, probably cheaper too. – DylanB Sep 04 '15 at 00:25
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    Depends on what you mean by fail. Plenty of people benefit from a degree that they were not very motivated to study for. – Jessica B Sep 04 '15 at 06:43
  • This whole discussion is about STEM. I had in mind specifically science/math for people intending to do research. – math_lover Sep 07 '15 at 16:40
  • @JoshuaBenabou You know, I've had some incredibly talented students in my classes. Some of them I managed to get to come to my office hours. They learned by far much more than they would have from just reading a book. So sure, if it's a huge class and it's targetting students below you, I get that. But if it's a small class where you can engage the instructor, or even better you talk to the instructor 1 on 1, you'll learn dramatically more. – Joel Sep 08 '15 at 04:50
  • @JoshuaBenabou And someone intending to do research isn't going to learn that from a book. If you want to do research - the best thing to do would be to get to the prof's office and talk about what you're doing in the class and how/if that relates to the prof's research. Remember if you're going to do a PhD one day, you'll want a letter of recommendation. A letter of recommendation looks much better if it shows signs that the prof knows who you are. – Joel Sep 08 '15 at 05:07
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Repetition increases retention. Information encountered in both a textbook and a lecture will be remembered better than information encountered in only one. Neither textbooks nor lecture are optimal learning tools.

Anonymous Physicist
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    This sounds like a maxim. Do you have scholarly support for these statements? –  Sep 03 '15 at 01:13
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    Repetition increases retention. So then is reading the book twice just as good as reading the book and attending a lecture? – ff524 Sep 03 '15 at 02:44
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    Getting the same info from two different sources is more effective even when wording is the same: Multiple source effect. – emptyother Sep 03 '15 at 04:16
  • @CreationEdge there are many published experiments addressing review. – Anonymous Physicist Sep 03 '15 at 04:24
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    Then shouldn't it be easy to find one to cite for your answer? Do those studies address review of different material using different mediums (such as your claim of lecture as a review of textbook?) –  Sep 03 '15 at 04:26
  • @TomA.Vibeto: You linked to a WP article on social proof, with a subsection titled "multiple source effect." It doesn't support your claim and doesn't have anything to do with education. –  Sep 03 '15 at 14:29
  • This is a possible reasonable justification for lecturing. However, I think it would apply mainly to the minority of subjects where retention of information is the main task. There are subjects that have a lot of this, e.g., anatomy or a foreign language, but I don't think it applies at all to most college-level subjects, where the challenges are intellectual. Also, lecturing tends to be a very poor way to reinforce retention of information, because it's passive. People retain information much better when they talk about it themselves, use it to do something, debate it, etc. –  Sep 03 '15 at 14:32
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I have seen the effectiveness of lectures through teaching ground (in class) courses and online courses.

My ground courses use lectures and a textbook as a teaching method whereas my online courses only use the textbook (I'll post helpful notes such as "On chapter 3 disregard pages 50-52" but other than that and answering emails there's nothing but the textbook - I use Blackboard in case that matters at all)

What I've noticed by teaching the same course through online and ground is that students almost always retain more information during the ground courses where there are both lectures and the textbook. Not only can students read the course material but they can also hear it and visualize it in some cases.

A textbook can also sometimes be difficult to follow for some students. For example:

When I was taking an accounting course during my undergrad I took it online - HUGE mistake. I ended up having to drop the course after 2 weeks because I didn't understand anything that was in the book. The next semester I took the same course as a ground course that used the same textbook and lectures. I passed the class with the top score among my classmates and I'll never forget what my professor said on the first day of class

"Don't read the textbook first. If you read the textbook first you'll be confused and filling up my inbox. Attend lectures and then read the textbook to reenforce what you learned."

Some students can follow a textbook and do well is almost any course. Others can just listen to someone talk, take notes, and do well in the course. There are also those who need both resources to retain the information. Using both methods (lectures and textbooks) will cater to all 3 of those student segments.

Memj
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In my experience, lectures are almost always worthless. You learn more in 30 minutes of reading than in 4 hours of lectures. Still, some people prefer lectures, and their preferences seem to be empirically justified.

In a similar way, I find it almost impossible to have a productive face-to-face discussion. Offline discussions work so much better, because you can always think about the issue for a few hours before replying. Again, other people seem to be more productive in face-to-face discussions than in offline discussions.

These two issues are probably related. Maybe some people are better at processing real-time information, while others process information in a more asynchronous fashion.

Jouni Sirén
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  • So I am to conclude that, indeed, except in a few cases like those I mentioned, there really is no point... – math_lover Sep 03 '15 at 02:05
  • @JoshuaBenabou: You need to work out whether lectures are your thing. If you can get by without them, then try. One thing is that you may not know exactly what material from the book you need to learn, especially if the lectures and textbook diverge. – Dave Clarke Sep 03 '15 at 08:08
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    If you believe that you can learn quantum physics without a lecture then good luck. – Alexandros Sep 03 '15 at 08:29
  • Funnily enough I have worked through most of the Feynam Lectures: Volume 3 this summer. It is an introductory text, but it doesn't seem any harder to learn than, say, multivariable calculus... – math_lover Sep 05 '15 at 21:17
  • That is not say that I know quantum mechanics. I'm just pointing out that in principle a good textbook could replace a lecture to learn a topic. To master a topic you probably need the help of a teacher. – math_lover Sep 07 '15 at 16:42
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One aspect that doesn't seem to have been mentioned so far (pointed out to me by a colleague earlier this week): the goal of a textbook and the goal of a course are different. A textbook is typically written to be used in many settings for one or more courses, and is meant to fit a broader curriculum than whatever specific course you are taking. For instance, when I lecture, say in a calculus class, I don't typically present all material or examples in every section we cover. So the lecture ends up being a more focused presentation than what is in the text.

Also, I often present things differently than the text, including some things not in the text. I think these things are mentioned in other answers, but let me emphasize the usefulness of seeing different presentations of material when learning a subject, which I think is different than pure repetition. It's pretty common when you reach a higher level of mathematics to learn a topic by reading several different books in tandem--seeing different perspectives helps you get a more complete picture and balances out deficiencies in specific presentations.

Kimball
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Some good answers here, but I don't think I've ever heard or read a better explanation than that of T.W. Korner's (full text available here). It's specifically about math lectures but still largely relevant for STEM.

Rather than attempt to summarize and do injustice to the full text, here are some choice quotes, starting with the bold claim:

"Many mathematicians find it easier to learn from lectures than from books."

On the advantages a good lecturer brings:

"If the mathematics is hard, the lecturer...[is] compelled to go slowly, but they can speed past the easy parts. In a book, the mathematics, whether hard or easy, slips by at the same steady pace."

"Most lecturers can sense when an audience is puzzled and respond by giving a new explanation or illustration."

"The lecturer is forced by the lecture format to concentrate on the essentials."

On learning by watching:

"A lecture presents the mathematics as a growing thing and not as a timeless snapshot. we learn more by watching a house being built than by inspecting it afterwards."

"we learn by watching experts [...] and imitating them. Unguided practice is generally useless and often worse than useless. People who teach themselves to program acquire a mass of bad programming habits... Mathematics textbooks show us how mathematicians write mathematics, but lectures show us how mathematicians do mathematics."

Chan-Ho Suh
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    This remind me of what Rota said of Church: It may be asked why anyone would bother to sit in a lecture which was the literal repetition of an available text. Such a question would betray an oversimplified view of what goes on in a classroom. What one really learns in class is what one does not know at the time one is learning. The person lecturing to us was logic incarnate. His pauses, hesitations, emphases, his betrayals of emotion (however rare) and sundry other nonverbal phenomena taught us a lot more logic than any written text could. – Kimball Sep 04 '15 at 15:18
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    (cont'd) We learned to think in unison with him as he spoke, as if following the demonstration of a calisthenics instructor. Church's course permanently improved the rigor of our reasoning. – Kimball Sep 04 '15 at 15:19
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    tl;dr: Good lectures are better than bad textbooks. – JeffE Sep 30 '15 at 10:54
  • @JeffE I don't agree with that "TL;DR". Korner's overall point is that even an excellent textbook will be written to convey information and involve the reader in a different way than a good lecture. – Chan-Ho Suh Sep 30 '15 at 13:38
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    @Chan-HoSuh But almost all of the specific criticisms compare good lectures to bad textbooks. Good textbooks help the reader speed past the easy parts. Good textbook authors are forced to concentrate on the essentials. Good textbooks present mathematics as a growing thing and not a timeless snapshot. Good textbooks show how mathematicians do mathematics. The only thing a good textbook can't do—at least, not yet—is realize when the reader is confused and adapt. – JeffE Sep 30 '15 at 13:41
  • @JeffE that's your opinion of what a good textbook is. J.P. Serre's textbooks are considered amongst the most exemplary examples of mathematical writing, but certainly they tend to present the material as "timeless". His style is to present the material as cogently and concisely as possible, i.e. a cleaned-up version, not how it was really done. Many mathematicians would say that is an important part of mathematics. Also, many good mathematical textbooks give fairly complete proofs. This will require at times going through details that are not essential to the ideas of the proof. – Chan-Ho Suh Sep 30 '15 at 13:54
  • Serre's textbooks are considered amongst the most exemplary examples of mathematical writing — I respectfully but forcefully disagree. Serre's books—and I've read several—are horrible textbooks, in my opinion. – JeffE Sep 30 '15 at 14:03
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    @JeffE I never said I agreed with that either, but it's undeniably true a great many mathematicians think they are exemplary. Anyway, whether you disagree with Korner or me is beside the point. You presented your comment as a summary of my answer (which is summarizing Korner). It was a bad summary, contrary to the entire spirit of the answer. – Chan-Ho Suh Sep 30 '15 at 14:05
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    I don't see a contradiction in the views of Serre's books here. Exemplary mathematical writing is not the same as exemplary mathematical textbook writing. – Mark Meckes Sep 30 '15 at 17:29
  • @Chan-HoSuh Hmm "Unguided practice is generally useless and often worse than useless" is very worrying. Could you please elaborate on how this relates to mathematics? I usually have trouble following lectures and study on my own; I want to make sure this is not a mistake. – Ovi Jan 04 '18 at 04:56
  • @Ovi Unguided practice can be dangerous if you learn bad habits. That's not to say it's a mistake to study on your own, just be aware you may be doing things that are counter-productive in the long-run. If you have trouble following lectures, there are probably things about the material you aren't really getting. Digesting other people's explanations helps grasp concepts more fully, and so does explaining to other people. Ideally a good student-teacher relationship provides that. – Chan-Ho Suh Jan 20 '18 at 18:05
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My lectures are designed to compliment the book, not mirror the book. Similarly, the book is a supplement to my lectures, not a summary of my lectures.

When a professor does little more than rehash the content of the assigned readings, then, for all practical purposes, students can either read the book, or attend the lecture. There may be some benefit to doing both, but doing one alone might well suffice.

That said, the authors of a book don't have my experiences; they can't tell my "war stories." They don't know where students had trouble understanding concepts last year. I can also offer a critical analysis of the text, perhaps even disagreeing with something in the book while presenting opposing views. I can also relate course material to current events, where publishers lag a year or more behind.

In short, there are several ways instructors can use class time to expound upon the foundation laid by the assigned readings.

J.R.
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The lecturer can react to the audience, which a book can't. You can ask the lecturer to clarify, to solve another example.

vonbrand
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    Yes the instructor can do these things, but a lecture is not nessecary for these things to happen. Why not read the textbook outside the classroom and then come to class to work on problems, like office hours in class. – math_lover Sep 02 '15 at 22:48
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    Answering students' questions is not lecturing. – Anonymous Physicist Sep 02 '15 at 23:22
  • @AnonymousPhysicist, it isn't, but a lecture certainly is a meeting where this should happen. – vonbrand Sep 03 '15 at 00:27
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    @JoshuaBenabou, that is called "flipped class". – vonbrand Sep 03 '15 at 00:28
  • Yes this flipped class thing makes a lot more sense to me. Why is this not more common.... – math_lover Sep 03 '15 at 02:00
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    @JoshuaBenabou: That might make a great separate question on this site. –  Sep 03 '15 at 03:07
  • @AnonymousPhysicist: Not in itself, but answering a question can often be a springboard for expanding on an idea or even introducing a new one and hence in effect be part of a lecture. – Brian M. Scott Sep 07 '15 at 07:27
  • @JoshuaBenabou " Why not read the textbook outside the classroom and then come to class to work on problems" What you're describing is called a flipped classroom. These have proven very useful in many contexts. Lots of research into them. – Joel Sep 08 '15 at 05:11
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It depends on the lecture. If it is simply just a summary of the textbook, then it may not be very helpful. But a lecture that is interactive, uses the Socratic Method, and is similar to storytelling (as Peter pointed out), is very effective. Sometimes the material is so difficult, that you need a professor to facilitate the learning. Finally, an expert can inspire learning in ways that an expert textbook can't.

Edwin Torres
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Usually in science it's not all about being locked up in an office and learning and to acquire as much knowledge as possible, but also about meeting and discussing.

Let us assume we have a textbook that relates perfectly to the student's personality, his background, his prior knowledge, and is perfectly aligned with the course's aims.

Let us further assume that the textbook is accurate, up-to-date, stimulates reflection of the material, and relates the lessons learned to the student's past and future (professional) life.

Let us assume we have a lecture that achieves the same.

A good lecture will add to what a good textbook provides:

  • a platform for interaction with an expert in the field,
  • a platform for social/peer interaction,
  • a platform for networking,
  • a platform for scientic discourse on a small scale.

Not considering the likelihood of establishing either a textbook or a lecture that actually meets above assumptions, I think the "social" aspects of a lecture outweigh the theoretical throughput of information one can feed into a student's head.

Yes, I think colloquia and seminars do even better serve this purpose than a lecture.

Yes, I admit, the number of lectures not worth attending is probably larger than the number of textbooks not worth working through. But this strongly depends on the place you study at. If you're not satisfied at your current place you might try for a change.

moooeeeep
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I've routinely found that the big advantage of having a teacher over reading a book is that a teacher can answer questions. I often have the experience when trying to learn something from a book that some question comes to my mind, and I search through the book and spend considerable time trying to find the answer. Sometimes I never find the answer. But a human teacher who knows the subject can answer immediately. Or, if I don't understand something, with a human teacher I can ask and the teacher can attempt to explain the idea a different way, and can adapt his explanation to the specific difficulties that I express. With a book, the writer may try to explain the same idea in multiple ways. But usually not. And even if he does, he can't adapt those explanations to every reader, he can only give maybe two or three variations. When I was in college, I had many times that I engaged a teacher in a back-and-forth conversation until I was sure I understood the concept.

If by "lecture" you mean the lecturer enters the room, gives his speech, and leaves, without allowing for any questions, then okay, what I just said doesn't apply. Others have made some relevant points, like some people may learn better by hearing than by reading, that a student's personality may be such that he will listen to a speaker but is unable to concentrate on a book, a student may show up for a lecture who wouldn't bother to read the book, etc. I won't repeat what others have said any further, I think they've made the relevant points. But really, if you have a human lecturer, they are almost always willing to answer questions.

I've seen some advertisements for video lecture series that say things like "now you don't have to try to learn from a book, you can have the advantage of learning from the best teachers in the world". My usual reaction is: No. For me, watching a video of a lecture is usually inferior to reading a book. The advantage of the human teacher is that I can ask questions, but of course a video teacher cannot answer. There are cases, of course, where a video is superior to a printed book: a video can show action that a book can only describe or perhaps show still photos. So if you want to learn how to perform some physical action, like how to play golf or replace a transmission filter or whatever, a video might be able to show you in ways that a book could not. That could also be true of a human teacher: he could demonstrate steps in a process in ways that a book could not.

Jay
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Interesting question. I've often asked myself the same question during my undergraduate years. You shouldn't just attend all lectures because not all will be useful. You should also not just ignore all lectures and study from a book. Its a judgement you have to make personally in finding the right balance. A few points might help: the subject, the lecturer and the student's preferred style of learning.

  1. Subject: There are certain subjects that are quite easy to learn from a textbook. For example I would say biological sciences/history should be fairly straight forward to read from a book-in fact its often necessary to get a good background from a book in order to make the most of a fast paced lecture. One advantage of attending lectures though is to learn about new or cutting edge knowledge in a particular field. A lecture can also give you useful insights that you've never thought about during your personal reading. By attending a lecture, you often get a feel for what a lecturer cares about and hence what's likely to come out in your exams.

  2. The lecturer: I think good lecturers have a way of injecting life into their subjects beyond anything you can experience from a book. However, habits such as reading directly what's already on the powerpoint slide just doesn't motivate students-you might as well just read the slide in your room. A student will definitely get more out a very interactive class and get to learn from other student's mistakes. Other students often ask questions that you're too shy to ask yourself and you learn from it. So in summary, attend the lectures of the really good lecturers on your course. Students are good at spotting good lecturers and their classes are often very packed.

  3. Preferred learning style: I think its important to get to know yourself and understand your preferred learning style. Some people learn a lot from lectures, some like making notes during lectures whilst others learn more from books. Whatever your learning style is though, there's a high chance you will learn from a very good lecture.

All in all, I think learning is a two way process: you can read all you can but you also need to obtain feedback from others to consolidate your learning. This you can get from very good lectures. At the end of the day, its your time and you have to decide how best to spend it.

John_dydx
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Think about a standard book: you can read it, or hear the audiobook.

The first one is at you pace, the second at the pace of the narrator. I remember I heard a text I read before, and found dull, read by a great narrator. And I found the text wonderful afterward. Because I was now able to catch the inner pace of the writer, the important turnpoint, and I needed someone to guide me.

A written book can be somehow flat. A great teacher can understand when a student is lost, and provide alternative explanation, or a different narrative. Or play with time.

Finally, some people cannot read, or do not have hands to turn pages. We do have our own means to remember or understand. There are different kinds of learners. Some are more visual, some auditive, some kinesthetic. It is likely that visual ones may be ok with the book, but sometimes senses merge, and sight + audition reinforce themselves.

Laurent Duval
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Lectures help lazy students who don't want to read the whole book and do all the exercises in the book, to pass the exam.

Count Iblis
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    And what is the point of passing the exam? (rhetorical question) – math_lover Sep 03 '15 at 03:49
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    @JoshuaBenabou: Likewise, what is the point of reading the textbook if attending the lecture allows you to acquire the needed knowledge? – cbeleites unhappy with SX Sep 07 '15 at 12:17
  • Because attending the lecture means you have to copy notes, notes which are written elsewhere. And it means you have to go at the pace of the lecturer. And it means you are less flexible time wise - what if its a nice day and you want to sit outside and read the textbook instead of sitting for 3 hours in a crowded lecture hall. – math_lover Sep 07 '15 at 19:37
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Everyone learns in a different way. There are a variety of different learners. In this I mean that some people may be able to grasp and understand the material and information better by hearing someone speak or by seeing it in written words. Some have combined learning styles, while others have a preference for one type of learning. There is a wide variety of ways that a professor or teacher can give the material to the student. The best would be for a teacher to give students multiple means of understanding or getting the information, as to not leave any one behind. If only this was done in more education settings, it would be ideal.

Genevie
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    Learning styles are only a preference. They do not indicate the effectiveness of a teaching method. – Anonymous Physicist Sep 02 '15 at 21:26
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    yes, you have a valid point. But I think if some if there are more types of the same material, it does help the individual learn in a more efficient way. But I guess this also goes into educational theory and personal or intellectual opinions on the topic. – Genevie Sep 02 '15 at 21:39
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    "Learning styles" is quackery, not science. Please don't propagate harmful myths. – 410 gone Sep 02 '15 at 22:11
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    @EnergyNumbers, quackery may be too strong a word. Learning styles are preferences, and those preferences appear very consistently in experiments. Businesses that promote learning styles as a useful tool may be dishonest, though. – Anonymous Physicist Sep 02 '15 at 23:21
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    @AnonymousPhysicist: The answer isn't just stating that learning styles exist as preferences, it's claiming that catering to them is educationally beneficial. That isn't true. See Pashler et al., "Learning Styles: Concepts and Evidence," http://psi.sagepub.com/content/9/3/105.abstract . –  Sep 03 '15 at 00:12
  • @BenCrowell "Not yet well studied" and "isn't true" are kinda far apart, don't you think? – Please stop being evil Sep 06 '15 at 03:28
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A lecture involves the medium of audio, and some people find this medium more conducive, or the combination of the whiteboard and audio to be more conducive to absorbing new information. Besides this it is to some extent a social experience and a time-constrained activity, the latter helping people with low self-discipline or self-motivational capability, pace their study. To others it might be a nuisance. Notwithstanding the other analyses about the historical roots and relation to modern technology, I think this is one succinct response to the question.

Personally, I find that lectures should be more of a thing of the past as things go forward, but finding the right replacement, or evolution, should be done with experimentation and care.

matanox
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Learning from lectures alone is very slow. Learning from books alone is faster. Learning from both books and lectures at the same time is very fast.

Edit: Since this answer is apparently unpopular, let me explain it a little bit more clearly. I have a PhD in Chemical Engineering and taught college-level chemistry for a few years, so I know something about how people learn difficult material and what makes a class effective. I don't have research data to back up these statements, so it is possible that other people would have a different experience. However, I have never met a person who did. I don't mean I have never met a person who did well in school without going to lectures, or without reading the book. What I mean is, I have never met a person who did not learn fastest from both lectures and the book.

Yes, you can learn via either method alone, and different people tend to learn more easily from one or other. It is also possible that a good lecturer can be more effective than a bad book, and vice versa.

My statement assumes that the quality of both the lecturer and the book are good (or at least equivalent), and is about efficiency - how much time/effort does it take to learn something. The reason books are more efficient than lectures in general has to do with information bandwidth. A book can communicate more complex material in a shorter time than a lecture can. The reason that lectures in conjunction with books are the most effective way to learn is that a good lecture can tell you what parts of the book to focus on - a good teacher points out the most important details. It also gives you a different view of the same material, and reinforces memory through repetition.

thomij
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    What evidence do you have of this? Not everyone learns the same way and some students struggle to learn anything from a textbook but can pass a course on lectures alone. – Memj Sep 03 '15 at 06:47
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    No, it is not. Spending 4 hours per week for a semester is 60+ hours where trying to learn differential equations from a book would take much longer. – Alexandros Sep 03 '15 at 09:35
  • @Memj I taught for several years and have a PhD, so I've taken lots of classes. This statement is based on my personal experience and observation of peers and students.

    Your statement is not incorrect, but I think you missed the point of mine.

     – thomij Sep 03 '15 at 15:51
  • @Alexandros - I do not think you can learn D.E. just by sitting in lectures. I am sure you would need to practice at some point, and you will get much more out of your practice time with a book than with lecture notes alone. – thomij Sep 03 '15 at 15:51
  • @thomj. 2 hours for 1 lecture and 1 hour to revisit / redo the exercises done in the lecture is enough to learn DE. It worked for me and many others, without even opening the book, by just reading from my notes and lecturer's handouts. Learning straight from the book without the lecture will be much-much slower. – Alexandros Sep 03 '15 at 15:54
  • @Alexandros - I don't think that what you are saying is contradicting what I am saying. – thomij Sep 03 '15 at 15:56
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The Cone of Learning is the key to the answer. We retain a lot more of what we hear than what we read silently.

Cone of Learning

It's analogous (though not as extreme) as arguing that music students who can read notes don't need to listen to music, they can just read the sheet music. You're not stimulating as wide a range of nerve receptors.

(less relevantly, as someone who has a reading disability (but went to an Ivy League university), I can assure you from personal experience that I got 85% of my knowledge from lectures and 15% from textbooks, though I tried sincerely hard to do all the reading assignments.)

Sridhar Sarnobat
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