Meaning of sampling for secondary school students

Resumen

We present an assessment study of 302 secondary students’ intuitive understanding of sampling. We analyse the participants’ answers to a task where they are asked to provide four probable values for the number of heads when throwing 100 times a fair coin. The statistical analysis of the values provided by the students suggests a good understanding of the relationships between the population and sample proportions. However, the variability of the sample proportion is overestimated and equiprobability, positive and negative recency biases were observed, especially within the younger group of students. The results suggest the need to improve the teaching of sampling and to provide students with some experience of the random variability within different samples of the same population.