An instrument for measuring performance in geometry based on the van Hiele model

In this paper we present the process of constructing a test for assessing student performance in geometry corresponding to the first year of Secondary Education. The main goal was to detect student errors in the understanding of geometry in order to develop a proposal according to the Van Hiele teaching model, explained in this paper. Our research methodology took into account reliability using Cronbach's alpha coefficient, as well as the construct validity, with the extraction of 13 factors that accounted for a high percentage of variance. This result leads us to conclude that the instrument constructed has the appropriate technical and pedagogical features to be considered an original and significant contribution to the field of geometry teaching. The final version of the test constructed after the extraction of factors is shown in the Appendix. Key words: Assessment, geometric concepts, mathematics curriculum, research, Van Hiele Model.