Importance of designing experiments

At work, we are currently editing a brochure on designing and carrying out lab courses, and we are working on a lot of projects which aim at redesigning labs. And one question that comes up all the time is this: Does it really make a difference whether students design an experiment themselves or whether they carry out an experiment that was set up for them beforehand?

There is a nice paper, “Spending Time On Design: Does It Hurt Physics Learning?” by Etkina et al., 2007, that sets out to answer exactly this question. They are wondering: Are students in design labs able to transfer the scientific abilities to new content the next semester?

In their context, “design labs”are labs in which students design their own experiments. “Scaffolding” is provided, meaning that questions the students work on focus on the individual steps of the scientific process. The students work is guided by TAs who ask questions in response to being asked questions, but who don’t give answers. Non-Design labs, on the other hand use the same equipment, the same number or more experiments, and a guided write-up. Students have to, for example, draw free-body diagrams etc to solve problems, but theoretical assumptions were provided in the text. In this type of lab, TAs provide an overview in the beginning and do answer questions.

On the midterm and final exam, the authors find that the design group outperformed the other group, especially when they had to identify and analyze assumptions. And the difference persisted even a semester later, during which both groups had performed design labs.

So I guess yes, it does make a difference. And when we are redesigning lab courses, we should try to include as much design by the students as possible if our goal is to help them become scientists.

Eugenia Etkina, Alan Van Heuvelen, Anna Karelina, Maria Ruibal-Villasenor, & David Rosengrant (2007). Spending Time On Design: Does It Hurt Physics Learning? AIP Conf. Proc. 951 DOI: 10.1063/1.2820955

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