Tuesday, January 25, 2011

Answering a complex problem after discussing it in tutorial

My genetics students are complaining about the way I've designed the tutorials.  I have them spend the first part of each two-hour tutorial in a structured discussion of the topics covered by the past week's classes, and the second half working on a complex genetics problem.  It's this second part that's generating the complaints.

They're given the problem in advance, and are asked to print it out and make a preliminary attempt at it before tutorial.  I've told them that this attempt can be quite superficial; it's only worth 1 point (out of 5).  They turn in this attempt at the start of tutorial, and are given a blank copy of the problem to work on.  The students then work on the problem in groups of 3-4 at the chalkboards.  (This classroom is in the old math building so it has lovely chalkboards filling three walls.)  Different groups then explain to the class their suggested answers to the different parts of the problem, and students discuss these answers.  They also discuss how the problem might be adapted or modified for use in different settings, for example, changing the organism so it can be reused on a test, or making part of it into a shorter stand-alone problem.  (In future we'll try to get them to also explicitly discuss what is needed for a good written answer to the problem, but they're not ready for that yet.)

All this seems to be OK with them.  But the final step is for each student to write out a careful answer to the problem they've been discussing, as if this was an exam setting.  These answers are handed in and marked; they're worth 4 points.  At present the group work is left on the chalkboards while students are writing their answers, but I've told them that in a few weeks we'll start erasing the boards before they write their answers.

Students are complaining that this is a waste of their time, that they don't learn anything by having to write answers after they've already seen how the problem should be answered, and that they would learn more by spending the time in additional discussion.  I disagree - I think that observing the right answer doesn't lead to much learning, and that having to apply what they've just observed by creating a written answer adds a lot.

In tomorrow's lecture I'm going to show them some data that might help them see the value in this.  It's from a paper that just appeared in Science (Karpicke and Blunt).  In both of the two studies they describe, the authors had students spend 5 minutes reading a half-page of text about a biological topic, and then consolidate what they'd read in various ways.  The students were then asked to predict how much they would remember a week later.  A week later they were tested on each topic.

In the first study the students either (i) did nothing more, (ii) reread the text three more times, (iii) spent 25 minutes making a concept map with the text, or (iv) tested their recall immediately by writing about it for 10 minutes, then reread the text, and retested their recall.  In the second study the students either (v) spent 25 minutes making a concept map or (vi) tested their recall, reread the text, and retested their recall.  In the first study each student read only one text and was tested a week later with a short-answer test.  In the second each student was given two texts, one learned with a concept map and one with recall testing, and these were tested a week later using either a short-answer test or a concept map (in randomized combinations). 

In both studies the students predicted that they'd remember more with the non-testing methods, but in the post-tests they always scored substantially higher when they had consolidated their reading by testing their recall.  Here are edited versions of their graphs:

All the data

Part of the data, that I'll describe to the students

I'm going to show my students this study in tomorrow's lecture, and I'm going to give them two conclusions:  First, people are not very good judges of how much they've learned.  (So my students should realize that their opinions of how much they learn by different tutorial activities may well be mistaken.)  Second, testing oneself is an excellent way to learn.  (So my students should realize that having to develop a written answer after a discussion is a valuable way to reinforce what they've discussed.)

This will take a few minutes that I could otherwise spend talking about mitosis but I think learning how to learn is more important.  The students have a mini-midterm coming up on Friday, so they should be fairly receptive to ideas about how to learn.  I don't expect that this new data will convince them all that my tutorial design is good (that's why I wrote 'should' above instead of 'will') but at least they'll realize that I'm not just doing it to to be mean.

1 comment:

Tyler said...

I agree with what you're trying to do. In UBC Computer Science, they do something similar. They encourage collaboration between people on assignments, but they tell people to wait at least an hour before they write down their answers. This ensures (or tries to, at least) that they actually understand the solution (and are able to recreate it on their own) as opposed to simply memorizing the solution as discussed and writing it down before one forgets it.