Students completed the same data collection instruments before and after instruction so that changes in their
conceptual understanding, scientific process skills and science attitudes can be spotted. These were concept test,
scientific process skills test and science attitude scale. The effectiveness of the teaching intervention was therefore
tested via these three instruments. The concept test was designed by the authors. It was designed to assess students’
understandings about ‘matter’. The test included 38 multiple choice questions at the outset. After piloting and
reliability analyses, 11 questions were discarded from the original test. The reliability (cronbach alfa coefficient)
was found as 0.857. So as to determine students’ scientific skills, scientific process skill test translated in Turkish by
Koray, Köksal, Özdemir & Presley (2007). It included 31 items, all of which were multiple choice questions. The
Kuder-Richardson-21 reliability coefficient was estimated as 0.81. In determination of students’ attitudes towards
science, science attitude scale developed by Ak..no..lu (2001) was benefited. The test included 20 items and it was a
5-point Likert scale, which ranged from strongly disagree to strongly agree. The reliability coefficient (cronbach alfa
coefficient) was found as 0.89.