Application: Lab Practica
In order to compliment our written tests, I’ve been experimenting with a lab test or lab practica. In many ways, the lab practica is an opposite to the written test. Where the written test is solitary, the practica depends on a team effort (students earn team grades). Where the written test rewards theoretical knowledge, the lab practica is as much an engineering challenge as a theoretical one. In the practica, strong laboratory skills, construction aptitude, common sense and interpersonal skills are critical to success. Surprisingly, the students who do the best on the written tests often have the most trouble with the practicas.
One simple example of a lab practica I have used pits students against two different battery powered cars. Students must predict where the cars will collide starting from arbitrary starting positions. Each group is able to use an array of tools to come up with any of many ways to predict where the cars collide. However they can’t manipulate both cars at once. When they are ready to test, they roll a dice to determine where each car will start and then have three minuets to use their solution method to predict the collision point and run the test.
Lab practicas are always intense class periods. With a significant portion of the lab practica grade relying solely on the accuracy of the predicted result for the single test, everyone usually gathers around the group who is about to test. Many groups will accurately predict results within 3% or less. Others are wildly off. Many times the smallest detail is responsible for huge errors – not unlike the NASA rocket that blew up because engineers forgot to convert English units to SI units.
Although students sometimes stress over practicas (uncertainty is inherent), I think they are very powerful. I rarely see students more focused then during a practica. All those soft skills suddenly become important – and students know it. Working together on something that matters to everyone is a huge team builder for physics groups.
The Big Picture
Although the lab practica format is specific to science, the larger idea of creating a real world performance based group test is applicable anywhere. I think there is hesitation about grading based on performance (outside of established performance-based subjects like the arts, speech, & foreign language) Additionally, having students earn grades as a group instead of individuals presents some obstacles. With care, I think both of these concerns can be managed to a reasonable level. And ultimately, adults are almost exclusively evaluated on performance instead of knowledge. Additionally, and especially in the future, team performance is often just as important as individual performance. It’s not perfectly fair, but then no one said it would be.