Middle school students' understanding of the role sample size plays in experimental probability

In this study, we examined the impact of an instructional program on sixth-grade students' understanding of experimental probability as it relates to sample size. As the number of trials in an experiment increases, the experimental probability is more likely to reflect the parent distribution; thus, smaller samples are more likely to yield unusual results. Results of this study indicate that, while typical middle school students are seemingly unaware of the relationship between experimental probability and sample size, appropriate cognitive activity focused on results of simulations of random phenomena can foster conceptual development. We witnessed growth that occurred as a result of key instructional tasks and concomitant mental activity.