Ramblings on teaching measurement uncertainty
Posted by Melissa on July 15, 2014
A couple of my colleagues and I have curricular development funds this summer to explore how we can better integrate computational and experimental activities in our curriculum. One of the topics that came up in our discussions yesterday was uncertainty: teaching propagation of uncertainty, getting students to appreciate what the uncertainty associated with a measurement really means, and the role of uncertainty in computational as well as experimental problems. As someone who teaches a lot of lab courses, I can’t tell you how often students will see two values, and their associated uncertainties, and say, “These values don’t agree because they don’t overlap within the uncertainty.” Argh!
As a department, we could probably do a better job making the discussion of uncertainty more coherent throughout our curriculum, and I know that I could do a better job of reinforcing the importance of the uncertainty in the classes I teach. One of my colleagues writes homework and exam problems regularly that require calculations with uncertainties. On the other hand, when I am not in the lab, I rarely include uncertainties in the problems that I ask students to tackle, which I think sends a message that uncertainty is peripheral.
Looking at the broader physics education landscape, when it comes to teaching uncertainty, there seem to be two groups: those who have heard of the current international standard (Evaluation of Measurement Data – Guide to the Expression of Uncertainty in Measurement – known as GUM and published in 1993) and those who haven’t. GUM only appeared on my radar two or three years ago. This spring was the first time I introduced students in our advanced lab course to the GUM method for handling uncertainty. If you aren’t familiar, Andy Buffler and Saalih Allie at the University of Cape Town and Fred Lubben at the University of York have developed some nice curricular materials for introducing the GUM approach in introductory physics classes (Curriculum and TPT article).
I wonder if GUM will ever gain a more significant following. It hasn’t made many inroads beyond the metrology community, and among educators, the implementation is not particularly widespread, despite the clarity with which I think it helps students navigate the maze of measurement uncertainty. For all you physics educators out there, have you heard of GUM? Do you use it in your curriculum? And if you do, what do you see as the benefits and drawbacks?