The effectiveness of the teaching intervention was approached from three different angles. These were conceptual
understanding, process skills and attitudes towards science. In the first of these, effectiveness of IBL teaching was
taken to mean helping students to produce correct answers to the concept test. Secondly, it was taken to mean
contributing students’ conceptual understanding by remedying their misconceptions prior to the teaching
intervention. As regards of the effectiveness of IBL on students’ process skills and attitudes, the term effectiveness
is taken to mean obtaining high scores in the two instruments aforementioned.