LAUSR

The objective of the research concerned here was to discover the difference in effectiveness among Levels 2, 3, and 4 of inquiry learning in improving students’ process skills. The research was a quasi-experimental study using the pretestposttest non-equivalent control group research design. Three sample groups were selected by means of cluster random sampling. They were three SMA (sekolah menengah atas, Indonesian senior high school) classes respectively serving as Experimental Group 1 were treated with inquiry learning of Level 3 (ILL-3), Experimental Group 2 were treated with inquiry learning of Level 4 (ILL-4) and Control Group were treated with inquiry learning of Level 2 (ILL-2). The research results indicate that there is significant difference in effectiveness among Levels 2, 3, and 4 of inquiry learning in improving students’ process skills. Inquiry learning of Level 3 (ILL-3) is more effective than inquiry learning of Level 2 (ILL-2) and Level 4 (ILL-4) in improving students’ process skills, as shown by the gain scores. It, therefore, indicates that, in improving students’ process skills, the teacher could apply inquiry learning of the levels that are appropriate for their scientific experience and competence, which are then to be raised to higher levels.