Wednesday, January 13, 2010

Calling on students randomly

While reading Teaching Unplugged by Scott Thornbury and Luke Meddings, I came across the following set of instructions in a fun activity called Best in 24:

Give everyone in the room, including yourself, a number. Roll the dice and ask the person corresponding to the number that comes up: What's the nicest thing you ate or drank in the last 24 hours?

I thought this over and realized there were two small flaws to this procedure.

First of all, this could be rather unwieldy in a large or extra large class. I have taught classes of 120 students before, and I can't imagine rolling 20 dice and counting up the numbers while students wait. However, I'm sure that Thornbury and Meddings intended this activity for more ideal class sizes.

Secondly, and more importantly, I wondered if rolling 2 or 3 dice and assigning numbers might make certain students more likely to be called on. I checked with a website called The Wizard of Odds, and realized that I was right. When rolling two dice, you are far more likely to roll a 6, 7 or 8, than a 2 or 12. And when rolling 3 dice, you will get a 9, 10, 11, or 12 more often than a 3 or an 18. In addition, when rolling two dice the number 1 never comes up, and with three dice, 1 and 2 never come up.

A solution? I have a few ideas for improving these instructions. One solution might be to use the odds for your own devious purposes. For example, give students who hardly ever speak out the numbers that you are more likely to roll, and give students who dominate the class the numbers you are less likely to roll.

If you want to get a real random number, you can use a random number generator. has a random number generator that is easy to use. Type in the range and click to get a random number instantly.

Another solution is to write everyone's name on index cards (or blank business cards) and shuffle them. This is probably the easiest solution, as you can make the cards once and use them many times.

One more (not so random) technique is to get a student to choose a second student to answer the question. This can be made more interesting by demanding that a student give a valid reason for passing the question on to a second student. If you think the reason is good enough, the second student must answer the question. If you think the reason is unacceptable, then the question goes to the first student. My students have come up with some pretty clever reasons!

Can you think of any other ways to call on students randomly that I haven't mentioned here?


Lindsay said...

Thanks Hall for a very interesting post and for pointing out alternatives to the dice rolling. I had always thought of dice as being totally random but you're right about the odds. There's a reason I suppose why I don't enjoy casinos!

I know people who have used Random org for other things, it seems like a very useful site. Cool widget.

Anonymous said...

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Ellen said...

Elementary teachers write each student's name on a Popsicle stick and keep them in a can.

After you've called on a student, you can either return the stick to the can to ensure randomness, or keep his/her stick out until all the names have been called.

Elementary teachers usually use option #2, though you do run the risk of the student checking out because they know they won't be called on again for awhile.