3.2.2. Data collecting tools
Data collecting tools in this study consisted of: 1. Chemical reaction learning achievement test. The test consists of 40 multiple-choice items which were selected from 60 items with item difficulty (p) index between 0.21 and 0.77, and the discrimination index (r) between 0.21 and 0.56 respectively.
2. Integrated science process skills test. The test consists of 30 multiple-choice items which were selected from 45 items with item difficulty (p) index between 0.33 and 0.77, and the discrimination index (r) between 0.36 and 0.65 respectively.
3.3. Implementation
The participants of this study were 24 Grade 8 students purposively sampled from the whole population of Grade8 students at Ban-Koksawang School during the first semester of academic year 2010. These students participated in the following process: 1) completed pre-tests of chemical reaction learning achievement and integrated science process skills, 2) performed eight scientific investigation activities of chemical reaction (16 hours) in which they
were required to submit a group scientific investigation report after finishing each activity, and 3) completed posttests of chemical reaction learning achievement and integrated science process skills (parallel to pre-test).
3.4. Data analysis
The collected data in this study included pre- and post-test scores of chemical reaction learning achievement and integrated process skills. Dependent-samples t-test analysis was performed to identify mean differences between the pre- and post-test scores for both chemical reaction learning achievement and integrated process skills.
4. Results and Discussion
The study results were categorized into achievement scores and integrated science process skills.