The implementation of Geogebra Softawre-Assited DDFC instructional model for improving student’ Van-Hiele geometry thingking skll

This research aims to discover the improvement of students’ VanHiele based on geometry thinking skills (visualization, analysis, ordering and deduction) through GeoGebra Software-assisted DDFC (Definition, Design, Formulation, and Communication) instructional model. This research employs quasi-experimental method with pretest and posttest control group design. The research was conducted in State of Junior High School (SMPN) 8 Bandung, Indonesia. The data population in the current research were grade VII students. The students of VIIF and VIIG classes were selected through random sampling. GeoGebra Softwareassisted DDFC Instructional model was applied in VII F, while conventional method was employed in VIIG. Based on the analysis, it can be concluded that: 1) the students’ geometrical level on each Van-Hiele’s thinking skill level (visualization, analysis, ordering and deduction) in GeoGebra Software-assisted DDFC instructional model and conventional learning model is improved from pretest to posttest, 2) there is a difference on students’ Van-Hiele geometry thinking skill degree of acquisition between the students who received GeoGebra software-assisted DDFC instructional model and conventional learning model, 3) thereis a difference on students’ Van-Hiele geometry thinking skill achievement between the students who received GeoGebra software-assisted DDFC instructional model and conventional learning model