Pre-service teachers and informal statistical inference: Exploring Their Reasoning During a Growing Samples Activity

Researchers have recently started focusing on the development of informal statistical inference (ISI) skills by primary school students. However, primary school teachers generally lack knowledge of ISI. In the literature, the growing samples heuristic is proposed as a way to learn to reason about ISI. The aim of this study was to explore pre-service teachers’ reasoning processes about ISI when they are engaged in a growing samples activity. Three classes of first-year pre-service teachers were asked to generalize to a population and to predict the graph of a larger sample during three rounds with increasing sample sizes. The content analysis revealed that most pre-service teachers described only the data and showed limited understanding of how a sample can represent the population.