As seen from Table 4, students’ alternative conceptions (SAC) and their difficulties changed over time (pre-, and post-test), which are generally positive. Their frequency varied considerably, and this data is also presented in the Table 4. As seen from the Table 4, positive conceptual changes occurred in students’ minds. This shows that students’ alternative conceptions
and difficulties decreased after the intervention. For example, percentage of the 5nd SAC decreased from 56% to 25% for pre- and post-tests. These differences were examined for statistical significance with paired sample t-test (see, Table 5).