DEVELOPMENT OF THE 5T-FSMD (FIVE TIER FLUIDS STATIC MENTAL-MODEL DIAGNOSTIC) INSTRUMENT TO IDENTIFY STUDENTS’ MENTAL MODEL PROFILES

Rachel Marchella (Physics Education Study Program, Universitas Pendidikan Indonesia, Indonesia)
Hera Novia (Physics Education Study Program, Universitas Pendidikan Indonesia, Indonesia)
Achmad Samsudin (Physics Education Study Program, Universitas Pendidikan Indonesia, Indonesia)
Haerul Pathoni (Physics Education Study Program, Universitas Jambi, Indonesia)
Evita Enggereini (Biology Education Study Program, Universitas Jambi, Indonesia)
Nor Farahwahidah Abdul Rahman (Faculty of Educational Sciences and Technology, University Technology Malaysia, Malaysia)

SCIENCE : Jurnal Inovasi Pendidikan Matematika dan IPA
Vol. 6 No. 3 (2026)

ABSTRACT Identifying students' mental models of static fluids remains challenging because conventional assessments are unable to comprehensively capture students' answers, reasoning, confidence levels, and the sources of their conceptions. This study aimed to develop a valid and reliable Five-Tier Fluids Static Mental-Model Diagnostic (5T-FSMD) instrument to identify students' mental model profiles on static fluid concepts. The study employed a Research and Development (R&D) approach using the 4D model (Define, Design, Develop, and Disseminate). The participants were 198 eleventh-grade senior high school students in Bandung who had studied static fluids. The instrument was validated by experts and empirically tested using Rasch Model analysis with Winsteps software. The results indicated that the instrument demonstrated valid content and construct validity, with coefficients ranging from 0.81 to 0.85. The Rasch analysis yielded a Raw Variance Explained value of 38.3%, person reliability of 0.77, item reliability of 0.98, and Cronbach's Alpha of 0.79. Thirteen of the fifteen items met the model fit criteria. Students' mental model profiles were dominated by the Synthesis Partial Understanding category (64.88%), followed by the Scientific Model (17.04%), Synthesis Misconception (12.05%), and Initial Model (6.03%), with the highest misconception found in the concept of hydrostatic pressure. Therefore, the 5T-FSMD instrument is suitable as a valid and reliable diagnostic assessment for identifying students' mental model profiles on static fluid concepts. ABSTRAK Identifikasi mental model peserta didik pada materi fluida statis masih menjadi tantangan karena asesmen konvensional belum mampu mengungkap jawaban, alasan, tingkat keyakinan, dan sumber terbentuknya konsepsi secara komprehensif. Penelitian ini bertujuan mengembangkan instrumen Five-Tier Fluids Static Mental-Model Diagnostic (5T-FSMD) yang valid dan reliabel untuk mengidentifikasi profil mental model peserta didik pada konsep fluida statis. Penelitian menggunakan metode Research and Development (R&D) dengan model pengembangan 4D (Define, Design, Develop, dan Disseminate). Subjek penelitian melibatkan 198 peserta didik kelas XI SMA di Kota Bandung yang telah mempelajari materi fluida statis. Validitas instrumen dinilai oleh ahli, sedangkan pengujian empiris dilakukan menggunakan analisis Rasch Model berbantuan perangkat lunak Winsteps. Hasil penelitian menunjukkan bahwa instrumen memiliki validitas isi dan konstruk yang valid dengan koefisien 0,81–0,85. Analisis Rasch menghasilkan Raw Variance Explained sebesar 38,3%, person reliability 0,77, item reliability 0,98, dan Cronbach's Alpha 0,79. Sebanyak 13 dari 15 butir memenuhi kriteria kesesuaian model. Profil mental model didominasi kategori Synthesis Partial Understanding (64,88%), diikuti Scientific Model (17,04%), Synthesis Misconception (12,05%), dan Initial Model (6,03%), dengan miskonsepsi tertinggi pada konsep tekanan hidrostatis. Instrumen 5T-FSMD layak digunakan sebagai asesmen diagnostik untuk mengidentifikasi profil mental model peserta didik pada materi fluida statis.