F. J. Kontur, K. de La Harpe, and N . B. Terry
I am trying currently trying to write my student materials for next year for my L2 Physics course. I want to base the mechanics unit on modeling instruction again, however I am trying to trim down from 2.5 terms of modeling to 2 terms (20 weeks). And although it seems like not much to trim down, every single lesson that I am getting rid of is painful.
I am trying to strike a balance between mastery of physics (with extended time spent of mechanics through a modeling instruction method), and some breadth to the course. I think with the extra 5-6 weeks we will do the optics unit. However I still want to have the conversation of “depth vs breadth” with the other teachers from around NZ and the powers who do control it all…
Back to homework. I am wondering do I write homework sets into my materials. As I wrote them I reflected on this year, and I realised only my top kids really completed any homework this year. Should I write it for next year? Should I enforce it?
A bit of reading led me to this article by F. J. Kontur, K. de La Harpe, and N . B. Terry (“The benefits of completing homework for students with different aptitudes in an introductory electricity and magnetism course”). They looked at not how a class may improve from homework, but instead how different aptitude students benefit from homework. They found “On average, successfully completing many homework problems correlated to better exam scores only for students with high physics aptitude. On the other hand, all other students showed zero or even a negative correlation between successful homework completion and exam performance. Low- and medium aptitude students who did more homework did no better and sometimes scored lower on exams than their low- and medium-aptitude peers who did less homework.” AHHH! What?! “Sometimes scored lower” …
“ it is worth noting that we as instructors assign homework to our students because we believe that all students will receive a learning benefit from doing homework. This belief is predicated on the idea that there is a strong positive correlation between making an honest effort to do well-chosen homework problems and student learning, qualities we attempt to measure using homework scores and exam scores. If there is no correlation between successful homework completion and exam scores, we should carefully rethink these assumptions, especially considering that assigning, completing, and grading homework is often a very time-intensive activity for both students and teachers. ”
Its worth noting that this article looked at the effect of both online homework, AND written homework. Online homework had negative correlations between completion rates and exam scores for medium and low aptitude students, and written homework had no correlation for these same students.
Not about homework, but I like this quote all the same: “As Redish et al. say, “We are frustrated by the tendency many students have to … spend a large amount of time memorizing long lists of uninterpreted facts or performing algorithmic solutions to large numbers of problems without giving any thought or trying to make sense of them”
Kelly O’Shea writes a good physics teaching blog I follow and she has posted on similar thoughts here.
So it looks like, for this course at least, homework will stay out of the course. Certainly something that needs to be further investigated… One possible avenue is “interleaving”. This means that homework doesnt just focus on one topic, but mixes up a number of different units. The research done on it (in maths) seems promising.