PZ Myers. 2005 Mar 13. An interesting teaching example. <http://pharyngula.org/index/weblog/an_interesting_teaching_example/>. Accessed 2008 Dec 01.
Posted on M00o93H7pQ09L8X1t49cHY01Z5j4TT91fGfr on Sunday, March 13, 2005
An interesting teaching example
On good ol' talk.origins, I discovered this well done example of how to teach students about science, so I had to steal it. I think I'm also going to try this in my freshman course next Fall. Thanks, Ron Okimoto!
I found that I had to teach the nature of science at both the undergraduate and graduate levels for the honors class and molecular genetics class that I taught. Even at the graduate level the understanding of science cannot be taken for granted. It turned into my one lecture speel. I'd hand out essays by Richard Feynman and Peter Medewar on the nature of science for the students to read and then we'd work on a jigsaw puzzle. I'd use the puzzle as an example of how science works. I'd use those cheap 100 piece kid puzzles that you can buy at WalMart. I found that the two puzzles that I purchased had an identical cut out pattern with different pictures.
The first thing that we'd do is turn over the pieces and I'd try and get the students to think about the problem. Just looking at the pieces, can they come to some sort of idea of what the picture was. Unless you have sometype of super genius that can assemble the pieces in their mind the students can only come up with vague ideas of what the picture might be. We do this in science all the time. Even the assumption that it will make a picture that they can make sense of should be pointed out to them. Try and get them to think about what they are doing. When they start to assemble the puzzle ask them what they are doing. None of the students I've had have tried the random assembly of just putting any two pieces together. Get them to understand that they are hypothesis testing by grouping the pieces by whatever character that they are using (color, pattern, shape). Ask them why their hypotheses fail so often. Get them to understand the problem that science deals with when you make assumptions based in incomplete data. If they were able to take all the characteristics of each piece and make a perfect analysis they would never be wrong in their choice of which pieces fit where, but using the mark I eyeball and only a limited set of characters you often make mistakes. You have to expect to be wrong quite often in science. You have to be able to test your hypotheses.
A few students always assemble the edge of the puzzle first. I point out that this is just what scientist try and do when they create a framework and build on it. We usually get the easiest pieces in place first and the edges are the easiest pieces to fit because they only have three interacting sides to consider. Science does what it can and builds on it. About this time someone notices that I've taken away the corner pieces. When they ask for the corners I ask them how they know that the puzzle has corners. It isn't a trick question. We make assumptions like this all the time, and it is based on our experience, but they can also see that some pieces are missing based on their expected square side and only two interacting edges. They have an hypothesis that something is missing and it is based on their experience and the physical evidence. I throw out the corners and they have to scratch their heads because I've given them the corners to another puzzle, but they still fit and they still complete the outside of the puzzle. I tell them that science is full of pieces that don't quite fit, but that are good enough to help us get a better idea of what it is that we are working on.
As the puzzle gets completed I make them note how the qualitative as well as quantitative nature of the hypotheses that they are testing improves as they acquire more knowledge of what the picture looks like. The picture never gets perfect because the corners don't match, but it is obviously good enough to get a pretty good idea of what the picture is.
I don't think that I've ever brought up creationism or ID in this lecture, but if you want to you can just state the fact that ID as a "concept" has never been able to place a piece in the puzzle of nature. They have tested quite a few pieces to see if they fit, but there isn't a single one left in place at the end of the day. Essentially, it is a concept with a 100% failure rate upon testing. The only pieces left on the board are the ones that haven't been tested yet. It has been found to be worse than just randomly picking any two pieces and trying them to see if they fit. If any student doesn't believe this, just ask them for a single piece that ID has placed in our scientific knowledge. You won't find a list of these things at the Discovery Institute because there are no ID scientific successes. The farce is that they have lists of scientists that were or are religious and state their scientific successes without telling anyone that usually these guys were responsible for kicking out an ID piece from where it didn't belong. These guys are known for their scientific contributions and not their ID contributions. This is why many scientists define science in such a way that ID is excluded from consideration. It simply has never worked, and it has been a monumental waste of time. Definitions like those that exclude ID get put in place to protect the incompetent from themselves. Most rational scientist can figure out for themselves that they can think about ID, but they can't really expect to use it for anything. Not a single success and a 100% failure rate upon testing is pretty convincing to most scientists.
I probably wouldn't bother bringing up Intelligent Design creationism in class, either, but I think the problem is even deeper than Ron suggests; creationists are more than just passive failures. Their strategy is to come up to the partially completed puzzle and shout that the rest of the pieces don't fit into the unfinished spaces. They grab two random pieces and shriek "They don't fit!" and declare the whole project doomed. Ultimately, what they'd like to do is so thoroughly disrupt the process that assembly can't progress further, since they take much more satisfaction in the holes and gaps than in the puzzle itself.
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Thank you thank you thank you! I am going to WalMart tomorrow(actually some other store, probably) and this exercise will be taught next week!
Using the same metaphor:
Quak-science (e.g., astrology) looks at one piece and tries from the look of that one piece to imagine how the whole picture looks like, without ever trying to actually put the pieces together.
IDC tries to put a couple of pieces together, makes a mistake, gives up, then declares that no human can ever be capable of doing the puzzle, i.e., admitting: I
am too stupid to do this puzzle, but since I am the smartest human ever, than only one smarter than me is God.
Related (somwhat): for several months now I have been looking for a website or a piece of software I can use to place a picture of my own choosing, break it into puzzle pieces, then put back the pieces one by one, finally copying some of the stages of the process into separate slides of a PowerPoint presentation I want to use for a talk. Does anyone know of such website or software? Please let me know if you do. I am pretty sure it is possible as I have seen puzzles in kids' educational games (before they grew out of them and moved on to slash and burn bloody gory games). - Brilliant tool! Your right PZ, the problem is much deeper and the possiblities of fleshing out the prioblems in ID "methodology" seem endless. Perhaps a little contest is in order on who can come up with the best application of this great little pedagogical tool?
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But here's a more realistic scenario. Mix two puzzles together.
I'm an epidemiologist and I have used the puzzle analogy for a long time as a metaphor for doing causal interpretation (but I never use the puzzles themselves; good idea). Here is how many disagreements among scientists arise: one thinks the piece is important and goes in the center; another it isn't important and is part of the edge (say the blue sky, not carrying much info); yet another thinks it's part of another puzzle altogether. And yet another that it isn't even a puzzle piece.
Pick up the average issue of Science and you will find 15 serious scientific disagreements in it. Disagreement in science is the norm, not the exception. Unfortunately, many lay people and most judges think that when two experts disagree, one of them is lying.
It's a puzzle. -
I think I'm also going to try this in my freshman course next Fall.
It sounds like more of a high school thing. The earlier you can teach students to conceptualise scientific methodology, the less likely they are to feel threatened and impugned by it because they don't understand it, and the more likely they are to become interested enough to be one of your future students. I think if there's a silver lining in this creationism nonsense, it's that science is getting a lot of publicity as a robust, relevant and pervasive aspect of society. We should be taking advantage of it. -
A great exercise
A virtue is that it shows science as a dynamic process. The closed nature of the assembly may be a drawback. Novices could easily conclude that the completed puzzle is what science is about. That the small puzzle is simply a step in the assembly of a much larger puzzle is implicit for us. Literal minds may need to assemble a series of increasingly larger puzzles to get the principle. It's disturbing to imagine what the most literal minds might require. -
Yes. One variation I think I'd make is to at least remove one whole edge of the puzzle, to emphasize the fact that we don't "finish" science in an hour session.
And Ben, I agree that this kind of thing would be better done in the high schools (or elementary school!), but we get a lot of intelligent, capable students who have had very little real science before they get to the university. Too often, what they have had is a bit of frog-chopping and a lot of rote memorization. -
I have just read this to my wife, a high school chemistry teacher (teaches honors chem to sophomores & second-year chem to juniors & seniors), and she is having me print out the text & comments thus far. She wants to do this with her classes, with some other changes/refinements--such as splitting the puzzle into two ~40% chunks and having half the class work on each. "But how do you know that you're all working on the same puzzle?" So thank you, one and all, for your comments, and rest assured that it will likely be appearing at at least one high school in the not-too-distant future.
JBWoodford#: Posted by on 03/13 at 09:39 PM -
Too often, what they have had is a bit of frog-chopping and a lot of rote memorization.
Exactly my point. If you save such a fundamental conceptual lesson for students who have voluntarily chosen a university degree with science courses, rather than in late primary school or early high school where science is compulsory, you're effectively shutting the gate after the horse has bolted. I actually had a limited interest in science until 7th grade, when I just happened to get a really good science teacher to spark my interest. You have to snare them early, and the longer you wait, the greater the chance that you'll lose them to apathy and ignorance and, as a result, pseudoscientific propaganda. -
Update: I did both the light-switch (http://sciencepolitics.blogspot.com/2005/03/teaching-scientific-method_111091712671945584.html) and the puzzle this morning. Both worked very well.
It took them about 10 minutes to figure out that corner-pieces were missing (upon which I gave them corners from the other puzzle). I did what PZ suggested and left out one whole edge. This made them much more uncomfortable than placing the corners from the wrong puzzle. In the end I gave them the edge-pieces with a big caveat that this is a part of the exercise that does not fit in the way science works, that perhaps that edge should be used to connect the puzzle to another puzzle and another and another, and all those little puzzles forming one huge puzzle, that is never finished.
A couple of neat things happened that made good teaching moments. First, one of the "wrong" corners turned out to be the key to linking two big parts that were, until then, sitting unconnected on the table. There was a side edge with a few more pieces added to it, and the bottom edge with many pieces added to it. The "wrong" corner piece linked those two portions and allowed them to see the outlines of the "big picture". I told them that although it makes them uncomfortable, the semi-correct piece was a key for subequent research and that in the end, they can always come back and reconsider the corner-piece and replace it with a correct one ("correct" meaning that it fits with color, pattern and shape, not just shape).
Second, the students had different "research styles": two started with edges, one homed in on one of the "characteristic" pieces (and eye of a cat) and built around it, another picked a random piece and worked on finding all its neighbors and so on. Each made progress, illustrating that different strategies and styles are all good, that there is no one "perfect" approach.
Finally, there was a point when one of the students found a piece that connected a lot of stuff together and, at that moment, ALL the students simulteneously oohed and aahed how that was a "key" piece. I stretched the metaphor further, pointing that this is like a study in Nature or Science, that everyone in the field ("consensus of the scientific community") agrees is a very important study.
I will definitely keep using both exercises in the future. -
Great exercise! I taught college bio for years and can see using that at the undergrad level, as well as in high school. This, i. e. musings on people's understanding about evolution and science, has been one of my favorite topics. "You can't believe in Evolution" is on that topic, and may be of interest to the people reading this blog. Archived here:
http://home.earthlink.net/~mmolvray/blogfiles/evol.htm
General link here: http://acid-test.blogspot.com/#: Posted by quixote http://acid-test.blogspot.com on 04/10 at 11:09 AM