Needs Analysis and Hypothetical Learning Trajectory for Plane Geometry Through Obor Sewu Batik Ethnomathematics in Grade Iv

Abstract

Elementary students may recognize familiar plane figures yet have difficulty describing defining properties and identifying the same figures in unfamiliar orientations. This study reports the preliminary design stage of Educational Design Research and aims to formulate a Hypothetical Learning Trajectory (HLT) for plane geometry using Obor Sewu batik as an ethnomathematical context to support Grade IV students’ spatial reasoning. The qualitative evidence comprised classroom observation in a Grade IV class at SD Negeri Mayangkawis II, Bojonegoro, a semi-structured interview with the classroom teacher, analysis of Phase B geometry learning outcomes in the Kurikulum Merdeka, and a theoretical review of deep learning, ethnomathematics, Van Hiele’s geometric thinking, and spatial ability. Observation and interview evidence were compared with curriculum expectations and theoretical constructs through thematic analysis; the resulting learning needs were then mapped onto Simon’s components of learning goals, learning activities, and conjectures of students’ thinking. The preliminary findings indicate that students’ responses were dominated by visual recognition, including difficulty identifying familiar figures after rotation and explaining defining properties. Instruction was also reported to rely mainly on two-dimensional textbook and whiteboard representations. Analysis of the Obor Sewu motif identified five visually approximated geometric elements associated with triangles and quadrilaterals. These findings informed a five-stage proposed HLT: cultural orientation, motif exploration, mathematical formalization, collaborative problem solving, and reflection-transfer. The HLT is a preliminary instructional design rather than evidence of effectiveness; it requires expert review and classroom implementation in subsequent design-research phases.