Importance Of The Formulation Of Hypothesis And Design Of Experiments In Introductory Laboratories

The scientific method is a basic and widely-used tool in many high-school and university laboratories. However, contrary to popular thought, what appears to be a simple and well-known methodology reveals its complexity when the students try to carry out an open or 'non-guided' lab-activity. Practical laboratory sessions are often limited by the teaching context or the uniformity of the experiments that the small lab-groups of students must carry out in each practical session. As a consequence of this, the first steps of the scientific method, i.e., hypothesis proposal and the subsequent design of the experiment are not usually defined by the students. Under these limiting conditions these two concepts-hypothesis and design-are usually presented to the students in a theoretical way instead of using an empirical approach. This work shows that putting into practice these first steps of the research work requires understanding many subtle aspects and acquiring mastery over a period of one or more academic years. We show that the theoretical teaching of these concepts involves misconceptions and we propose an introductory practical session that improves students' understanding.