Dot Physics

The basic idea of the student response system is that each student gets some electronical (or not – see below) device that lets them answer multiple-choice questions. (Science Geek Girl has a good summary of clickers also) A computer then displays the distribution of responses for the class. Simple, no? They are becoming super popular, and I really like them. I used to just use them for large enrollment lecture classes (like 100 students). However, this semester I started to use them in my intro physics course for science majors with just about 30 students. I didn’t realize the impact they had until one day they didn’t work. Here is my basic method for using them.

  • Ask an interesting multiple-choice question. These can be difficult to come up with, so I just steal them. Currently, I am using the text Matter and Interactions by Chabay and Sherwood. The instructors material for this text has some really good questions.
  • Let students vote. You don’t have to wait for everyone to vote, just most people. I encourage them to discuss with their neighbors if they need to.
  • Display the responses and then ask for volunteers (or call on someone if you know everyone’s name) to share their response and the reasoning behind their response.
  • If people are not inclined to share their ideas, you can ask for someone to describe their neighbor’s idea (then it is ok if they are wrong) – I don’t typically have a problem with students sharing. Sometimes a particular student will share too often, but that is easy to fix.
  • If most people agree on the correct answer, I can just move on. If not, I can either go over the answer or give them a hint and have them revote.

So, what happens if you don’t have ‘clickers’? Can’t you do this stuff anyway? The answer is that of course you can. However, I found a few differences (even using the same multiple-choice questions).

  • Response time. Without the clickers, someone was likely to respond within 10 seconds or less (10 seconds is a long time for a class to wait – time it yourself and see). With the clickers, clearly everyone has to wait. This is a good thing (waiting). It gives students time to really contemplate the answer which in turn gets more students involved.
  • Discussion. I think when there is a clicker, it is clear that everyone gets to answer. Even though these are anonymous responses, students are more careful about their choices. They are more likely to discuss their ideas with their neighbors (this is good).
  • Interest in the correct and incorrect answers. Without clickers, maybe a couple students answer the question and everyone else is waiting to ‘write it down’. With the clickers, the students have already invested some time into a particular answer. If it is not the correct answer they seem more interested in discussing the concepts involved.

So, I like clickers. In a pinch, if you do not have clickers, you could make response cards or have students vote by holding up their fingers. Neither of these seem to work as well as the clickers (don’t know why) but they are better than nothing.


  1. #1 Mike Kadin
    October 15, 2009

    I totally agree. I am a high school physics teacher and I have a set of these clickers for my classes which are all 25 students or less. Not only are they useful for all of the reasons you mentioned, but they also have a lot of value in tracking individual students over time. If you assign individual students their own clickers, the particular brand of clickers I use keeps track of their responses. You can give graded quizzes with them, or just use them to figure out which students are struggling and suggest to them that they come to your office house. They are pretty nice.

    I intend to blog on how I use them soon on my new website, take a looksee in the near future and I’ll have some more complete thoughts.

    You may also want to check out which accomplishes the same functionality, just with cell phones. Its nice for any ol’ crowd, not just your classes.

  2. #2 PG
    October 16, 2009

    Really? I’m still an undergraduate, and I’ve despised the classes I had that used clickers. It interrupts my train of thought when I’m trying to absorb and learn, which is like having an annoying friend keep trying to talk to you while you’re doing your homework. It almost always gives the impression (to me, and to a small sample of people I’ve taken classes with) that the professor is less interested in teaching, and more interested in generating statistics for him/herself. Maybe I’ve just never found classroom discussion that beneficial.

    I agree that the rules of interaction have to change with a large lecture hall, but again, I’m not sure that clickers are the best answer.

    I’m interested to hear more about it… I suppose pretty soon I’ll be TAing in grad school and I may need to use them myself.

  3. #3 Rhett
    October 16, 2009


    With anything, it can be used in an ineffective manner. Chalkboards can definitely be useful, but once I had this professor that just copied stuff from the book right onto the board. So, the same can be true for the clickers. Also, I think it is important to think about the goals of the classtime. If the point is to cover material, these clickers would just get in the way. For my class, I encourage them to read outside of class and then we use the clickers to discuss the more complicated parts.


    The cell phone clickers seems like a cool idea, I will have to check that out.

  4. #4 Florine
    October 16, 2009

    In a pinch, if you do not have clickers, you could make response cards or have students vote by holding up their fingers. Neither of these seem to work as well as the clickers (don’t know why) but they are better than nothing.

    One reason could be that with clickers your answer is not visible for the whole class to see. For one, students cannot copy each others answers (as they might when holding up hands), and it’s less intimidating for shy or insecure students to give their answer, even when they’re not sure it’s the right one.

  5. #5 Chris Goedde
    October 16, 2009

    I’ve been using clickers for the first time this quarter, and I agree. I do use them in more of a pure peer-instruction way: (a) vote. (b) student discuss with their neighbors, (c) revote.

    I agree with Florine; I think it works better than old-style analog voting (which I’ve also tried) because you can immediately display the graph of the results, so it’s easier for everyone to get a sense of what the range of thought is before the discussion. There’s often an audible response when the initial responses are posted, and my class usually give a little cheer if the second vote is close to unanimous. They still haven’t forgotten the second vote that was unanimous and wrong, though.

  6. #6 Joe Andersen
    October 18, 2009

    Eric Mazur ( integrates clickers into his e xcellent teaching strategy. I Tfed for him one semester and I think the students really enjoyed and benefitted from the whole program.

    And he has real statistics to back up claims that his method works.

  7. #7 Cartesian
    October 19, 2009

    It makes me remember that the strategy is not always the same for example in a country where I did study, it was good to correct the errors of the teacher during the lecture, and in an other one the teacher did not seem really happy about it.

  8. #8 Cartesian
    October 20, 2009

    I think that to encourage the student to correct the teacher, can be good in order to put him on the way to correct the actual theories by research.

  9. #9 Derek Bruff
    October 20, 2009

    PG raises an interesting point, one I haven’t seen frequently in studies of student reactions to the use of clickers. I’ll sometimes see the complaint “Now I have to pay attention during class,” but not “I’m already paying attention and this is an interruption.”

    I found provocative PG’s comment that using clickers almost gives the impression that the teacher isn’t interested in teaching, in part because it points to a deeper issue here. If my job as a teacher is to share content with my students, and it’s up to them to spend lecture time paying attention, taking notes, and making sense of that content as best they can, then I’ve set students like PG up to succeed. Here’s a student who can pay attention, take notes, and reflect on what they’re learning during lecture.

    The problem is that students like PG are relatively rare. Most students can’t pay attention and take notes and process what they’re hearing fast enough to keep up with the teacher. So instead they just take notes and hope to figure the material out later. Some of them do figure it out later, certainly, but in this situation, the teacher has put pretty much the entire burden of assimilating the information onto the students.

    Another approach is consider it my job as a teacher to design a learning experience for students that will help them make sense of the material. The students have some responsibility for learning (coming to class, paying attention, participating, turning their brains on, and so on), but most of the responsibility for orchestrating the learning experience falls on me the teacher (not all, but more). So when I ask my students a clicker question, it’s because that I, as the educator at the front of the room, feel that the students need a chance to test their learning at that point in the class session. That decision might not work as well for students like PG, but it might be a great decision for many other students in the class.

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