Wednesday, March 01, 2006

Class Times

At the University of Chicago most courses on Monday-Wednesday-Friday run 50 minutes each and on Tuesday-Thursday run 80 minutes. Many other universities have similar timings. Most professors seem to prefer the longer classes especially for graduate courses: You only have to teach two days a week, you don't have to recap as much and you get an extra ten minutes a week.

I prefer the 50 minute lectures. Many theorems fit nicely into these smaller lectures. These lectures are easier to prepare. But most importantly I remember struggling to keep focused as a student in those longer lectures and I don't want to subject my students to the same.

There are variations on the theme. I took a graduate cryptography class with Silvio Micali that went for three hours once a week. We did have a muffin break in the middle and Silvio has the personality to pull it off.

During my sabbatical year in Amsterdam I taught a short course that had 90 minute lectures. The students insisted on having a break in the middle. Most Dutch movies theaters inserted an intermission in the middle of movies. Apparently the Dutch have an attention span no longer than half of a soccer game. My kind of people.


  1. For myself, I tend to notice looking at my watch first around the 40 minute marker.

    At the center for teaching development at UCSD they recommend every 20 minutes or so giving the students a 2 minute break. That's not enough time to go to the bathroom, but the break can help them learn and remember the material better. It could probably create better opportunities to ask questions, too. In my experience it seems that just when one topic is complete, the professor will start the next topic too soon, closing that important window for lingering questions. After the second slide of the new topic is presented, a student would feel like they were distracting the class to ask about something 5 slides before.

  2. I find 50 minutes too short for a graduate course. There are too many recent results that I can't fit into 50 minutes. But that might be due to me never having had 50 minute classes as a student (neither undergrad, nor graduate).

    As an undergrad, I had classes with 45 minutes of lecture, 10 minute break and 45 more minutes of lecture. That was working quite well. Enough time to present the material and break in the middle makes it easier to stay focused.


  3. I prefer 3-times-a-week, 50 minutes
    certainly for ugrad, but also for gra

    a) If its 75 mintes the last 15 minutes
    might be wasted- they want to go home,
    and are distracted. And 75 minutes seems
    to short to give a break.

    b) You can spend an entire lecture going
    over HW or Doing examples.

    c) Nice self-contained lectures.

    d) (At least at Univ of MD) Since EVERY
    other prof teaches Tu-Th grad coures,
    my courses do not conflict with any others
    (DOWNSIDE- some STUDENTS only want to
    come in on Tu-Th. So nice to see
    Students with the arrogance of Full profs
    at such a young age :-) )

    bill g.

  4. On Dutch courses. While on an exchange, I took a 4 hour, once a week course at Utrecht University. The class went on forever, though we did have three 10 minute breaks. I also took a 3 hour algebraic number theory course at UvA with two breaks and the last 45 minutes dedicated to questions and examples. I guess the longer format did come in handy, since, for example, the number field sieve took all 3 hours to cover.

    These long courses came as quite a shock since the longest course I'd ever had was 75 minutes. I managed, but don't think I could have without the breaks in the middle.

    - Andy

  5. I've also seen the format with three hours and the last 45 minutes to 1 hour dedicated to questions. That actually worked; in this class the students had a lot of questions. It was a philosophy class, not math or CS, but I think it could extend to anything where you have enough talkative students.

  6. At my current grad school, we meet
    once a week for 110 minutes.

    In general, most of my fellow
    students find that after the first 45
    minutes or soon thereafter
    we are blankly copying down material
    with hope that it will help when
    we have to figure everything out
    ourself later....

    But at least the professors only have
    to teach once a week. And never
    really have to go into all the proof
    details, instead, just provide brief overviews and intuition.

    Seriously though,as must as we dislike
    the system, it is nice to not have work
    interrupted by having to goto pesky class...

  7. I'm starting now to be convinced that meeting three times a week for 50 minutes is much more conducive to learning.

    You'll have more material "in your mind" for a longer time. If it's all crammed into a single session, you might think about the highlights from it that evening and the next day, but by the time the next class rolls around, you probably wouldn't have thought about the material for several days already. (Homework can help get it back in your head, so perhaps the due date should be set to encourage the material to be in your head during what otherwise would be the lowest point in the weekly cycle.)

    A bit off topic: students also learn better the more immediate the feedback. There is nothing worse than taking a midterm and not seeing the results for over a week. Much better would be to have a discussion section or a handout available right after a midterm to show what "the answer" was. (This should also be the case when homework is due: go over the solution on that day in class, or at least post them.)

  8. For undergraduate material the 50 minute time-frame seems good.

    The problem as you get to graduate material is that some of the arguments don't fit and require so much state that you spend a third of the time resetting the state before you can get on to the new material.

    In a typically term there is probably a week's worth of additional material one can cover with 2 80 minute classes per week versus 3 50 minute classes even if you take a short break in the middle of the longer classes.

  9. Having sat through a once a week, 2.5 hour, no break lecture, I think it is a really bad idea unless the lecturer is really good at keeping tracking of when people are following and and helping to keep a big picture in mind. I definitely feel that 50 minutes is about the most technical mathematics I can really grok at one time before I start loosing the ability to concentrate on it as hard as I like.

    When I teach recitations I will often pause after working through a complicated problem for a good 20 or 30 seconds waiting for questions, because I know that although it feels like forever standing in front of the class, it gives people time to digest and figure out if they really have questions.

  10. "The problem as you get to graduate material is that some of the arguments don't fit and require so much state that you spend a third of the time resetting the state before you can get on to the new material."

    For such material, it's hard to concentrate for the whole 1.5 hour lecture anyway, so much of the details tend to be lost on the students anyway. So pick your poision =)

  11. i used to have 50 minute classes and i understand most of it. now i have 80 minute classes and i understand nothing, but read the lecture notes instead.

    I think 20 minute lectures 5 days a week is a good format. More complicated results should be divided into several small results if possible.

  12. "Most Dutch movies theaters inserted an intermission in the middle of movies. Apparently the Dutch have an attention span no longer than half of a soccer game."

    That's only for the cinemas showing Hollywood-type blockbuster movies. Dutch arthouse cinemas don't put an intermission unless the movie is *really* long (say > 3 hours).

    -- Ronald de Wolf