The undergraduate degree is structured such that students during later years engage in a cognitive apprenticeship where they are mentored by experts in an active research environment. Meanwhile, novice students struggle to develop the capacity to think and practice like scientists while immersed in an environment of didactic explanations about scientific concepts. We explored the variation in understanding of hypothesis testing and the articulation of testing methodologies, amongst first year science students, to develop categories of understanding and misunderstanding.
The methodology used an analysis of 350 matched student responses to pre- and post- surveys. The survey questions used ecological scenarios requiring students to generate a hypothesis and provide a protocol for testing it. The scenarios for the pre and post-surveys were different but were based in the same field biology context. Responses were coded using a phenomenographic protocol whereby categories were framed to encompass variation across all samples. Initial analysis failed to incorporate all the variation in the sample so the categories were redefined to incorporate the ideas of ‘stuck places’ and troublesome knowledge. This process led to a shift in categories to focus on key areas of confusion and thus highlighted the defining characteristics of hypothesis development and testing.
Results/Conclusions
The analysis highlighted key problems for beginning science students in the conceptual understanding of hypotheses and in their ability to formulate experimental protocols. Key categories of misunderstanding included both the concept of variables and their testable nature. The concept of prediction also caused problems and the distinctions between uni- and multi-variable hypotheses compounded these existing problems. The extent to which students could articulate hypotheses that were relevant or appropriate to the question was also identified as an area with significant issues. The relationship between the hypothesis and an appropriate testing protocol thus became a significant impediment when students attempted to articulate an understanding of the latter. The ‘doing’ (as in counting or measuring the relevant variable) was a concept which eluded many students, as was the essential role of control and replicate conditions.
The nature of the categories, and the inherent complexity of the relationships between them, provided us with a framework for designing inquiry activities in a new laboratory course curriculum. This focused on a mix of scaffolded and independent experimental investigations where students had numerous opportunities to discuss their conceptions of hypothesis testing, and put their ideas into practice.