Abstract
This study entailed the design, implementation, and evaluation of 2 versions of a teaching experiment that traced students' growth in probabilistic thinking. Twelve students drawn from the 4th and 5th grades (9- to 10-year-olds) of an elementary school in Lesotho, Southern Africa, took part in the investigation. Students in the 1st version focused on analyses of small-sample experimental data and sample space composition as strategies for tackling probability problems. In contrast, students in the 2nd version were challenged to make connections between large-sample experimental data (drawn from computer simulations) and sample-space composition after looking at small sample data and sample-space symmetry. Although there were no significant differences in probabilistic thinking levels of students who followed each version of the teaching experiment, analyses of quantitative and qualitative data indicate that each version had a noticeable impact on students' growth in probabilistic thinking. Additionally, results suggest that central conceptual structures similar to those observed in the domain of quantitative thought exist in the context of probabilistic thinking.