Teachers’ level of understanding geometry concepts vis-à-vis van Hiele’s geometric thinking model

Abstract

Understanding geometry has an impact on both the subsequent academic track and the real-life application of the learners. However, students’ performance and attitude in mathematics are declining. Thus, this study examined secondary school mathematics teachers’ levels of understanding of geometry based on van Hieles’ geometric thinking model. The van Hiele geometry test (VHGT) result was administered to 72 teachers who joined Wolaita Sodo University in Ethiopia for the PGDT program in the summer season. The test has used 25 multiple-choice items; five items for each level of the model were adopted. A content analysis of the Ethiopian mathematics syllabus was made to check the alignment of the material with the study context. It was proven that all the concepts covered by the test items are available in the syllabus. The study revealed that teachers lack the level of understanding that is relevant to teaching geometric concepts incorporated into the secondary school curriculum. In particular, participants’ mean score is 10.51 and STDEV 1.92. While the maximum score is 15, the minimum is 6, with a range of 9. While 2.8% of participant performance is below the levels, 97.2%, 59.7%, and 13.9% are able to attain the first, second, and third levels, respectively. No respondent was able to reach the fourth and fifth levels. Thus, intervention to enhance teachers’ level of understanding of geometry needs immediate attention. The problem needs special attention to break the vicious circle that today’s students are tomorrow’s teachers, who lack the skills to scaffold their students to benefit from the education system.