Chad's spot for various thoughts, musings, poetry, ideas and whatnot

Friday, December 07, 2007

Here at Gordon we're in finals week and I've given and graded my final exams for my two introductory physics classes. One of the big things that a lot of people don't realize about education is how important it is to assess every aspect of you students' learning but also how hard it can be to do. When I took physics as an undergrad, the emphasis was on assessing whether a student could solve a variety of problems with the assumption that to solve those problems a student had to have a good grasp of the conceptual material the the problem was related to. In the twenty or so years between my first physics class and now, that has been found to be a woefully inaccurate assumption. Work by Hestenes at Arizona State, Mazur at Harvard and Hake at Indiana have shown that just because a student can solve a problem, it doesn't mean the student knows much about the physics. In fact, in the physics courses that cater to the pre-med and other allied health students what a problem solving exam might show is only that the student is able to pattern match the test questions to previously worked examples. I know that when I taught these courses at the University of Florida as a graduate student, it was pretty apparent that the pre-med students focused on memorizing solutions and didn't have much conceptual understanding.

For that reason, not long after I started teaching as a career I began to test my students' conceptual understanding. Not only do I test the final understanding but I test the students' "previous knowledge state"; which is a fancy way of saying how much to they know walking in the door about the conceptual framework of Newtonian physics. A lot of really, really good research has been done on this by groups at the University of Washington, Dickinson College, Tufts University and the University of Oregon. (There are many others who are doing good work as well.) What they have shown is that students come into a physics class with a very robust picture of how the physical world works that is almost entirely wrong (Aristotelian actually). A lot of my class is built around getting the students to change how they think about the world as well as teaching them a structured problem-solving methodology.

All of this is to get the point that my physics students did great this semester. One why to measure performance is to compare how a student does on an assessment instrument (in my case a conceptual test) that is given both at the beginning and at the end of the class. The most common way to analyze the data is to calculate a "gain value" by looking at how much their score on the exam improved divided by the maximum it could have improved. Hake's research at Indiana of over 10,000 students showed that students taught in a standard lecture/lab format course had average learning gains of around 22% (how much did you pay for that course?). His data showed that students who were taught in some form of non-traditional format that emphasized interactive engagement in some way had average learning gains of around 60%. Interestingly enough, hake's research showed that there seemed to be a ceiling for the gain scores of about 70-72%.

Well, my engineering physics course (calculus-based introductory physics) showed an average learning gain of 79% and my allied health related course (algebra-based intro physics) had learning gains of 67%. Needless to say, I am really, really pleased with these numbers. Additionally, all but one of the students who started the calc-based course finished and two-thirds of the algebra-based students finished; both numbers being well above the national average much less the average for two-year colleges. I feel really good about the numbers and the classes.

I really can't take too much credit for the success as I'm using curricula developed by folks a hell of a lot smarter than me and I have had outstanding, hardworking, deeply engaged students this semester. For the methods I use to work, the students not only have to buy into the unconventional methods I use but they also have to put a lot of energy into the methods as they are pretty time intensive. Not all students do that but these ones sure did. I can certainly go into the Christmas break with a good feeling of a job well done by all involved.

Thanks for reading.

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