In this exploratory study the understandings demonstrated by primary students as a result of their involvement with the interactive CD package Astronomy Village: Investigating the Solar System were explored. Thirty-one students aged between 10 and 12 years, from two schools in rural New South Wales completed two tasks before and after the intervention. The first task was a 40-item multiple-choice test, traditionally used to evaluate students' understanding, and the second task was an open-response question. The results between pre and post-tests on the multiple-choice questions suggested students improved their content knowledge with a statistically significant difference recorded. The open-response question was analysed using the Structure of the Observed Learning Outcome (SOLO) Model. Approximately one-third of the students demonstrated an improved level of understanding, after the two-week intervention period, however, the magnitude of this change was not statistically significant according to a Wilcoxon signed rank test. The utilisation of the SOLO Model provided a qualitative insight into the change of students' understandings that complemented the quantitative results obtained from the multiple-choice test. As a consequence of this study, similar tasks are being used in the United States to evaluate software packages.