Abstract
This study aimed to enhance students’ learning achievement of chemical reactions and integrated science process skills by using
eight scientific investigation activities (16 hours). The participants, purposively selected, were 24 Grade 8 students at Ban-
Koksawang School in Buriram province of Thailand in the first academic semester of 2011. The research tools consisted of a
learning achievement test of chemical reaction and an integrated science process skills test. The dependent samples t-test analysis
resulted in the students obtaining a post-test score of achievement (mean 21.17, SD 6.20) significantly statistically higher than
that of the pre-test score (mean 15.00, SD 3.71) at the 0.05 level of significance. It also indicated that their post-test score of
integrated science process skills (mean 15.14, SD 3.55) was significantly statistically higher than that of the pre-test score (mean
10.08, SD 4.69) at the 0.05 level of significance. This study showed that the implementation of scientific investigation was
effective to promote students’ learning achievement of chemical reaction and to increase their integrated science process skills
since this learning approach allowed the students to use their science process skills to investigate and understand the concepts of
the activities.