This research is aim to analyze the effective of Guided-Inquiry model for improving process science skills. This research design which applied in this study was One-group Pre-test and Post-test 15 students of senior high school. The data were analyzed using Anova, N-gain and the paired t-test. The result showed that there was a significant improvement of students’ science process skill at a = 5%, the average N-gain of 1.06 was categorized high. The result of science process skill test before being taught with learning instrument developed has average pre-test is 60. The result is low because the ability of students who less understood the material and most of the students not yet accustomed to practice the science process skills, so many students are having trouble.

 

Based on tabel above shows the post-test results of students' science process skills that have increased with an average post-test value of 89. These results indicate that learning instrument developed through the guided Inquiry model have a positive effect on improving students' science process skills. Thus, The Guided-Inquiry Model to improving science process skill which was developed is effective.