All Other Things Equal: a study of science graduates solving control of variables problems

Abstract

The responses of science graduates to control of variables problems were investigated using problems in two content areas, biological (plant) and physical (pendulum), and two formats, experimental planning and interpretation of given data. While the pendulum planning problem and the interpretation problem in the plant context were relatively well answered, the pendulum interpretation problem and the plant planning problem proved to be particularly demanding. Inappropriate strategies which utilised prior and, with respect to these problems, irrelevant knowledge of plants and pendulums, and also a restricted understanding of ‘control’ in biological experiments, were adopted by many subjects. Possible reasons for the adoption of these strategies are discussed, together with some educational implications.