VALIDITY AND RELIABILITY ANALYSIS OF AN ENVIRONMENTALLY INTEGRATED SCIENCE LITERACY TEST USING RASCH MODEL

Abstract

This study aims to create an integrated assessment instrument for environmental science literacy focused on thermodynamics for high school students. The research methodology employed is Research and Development (R&D), specifically using the 4-D model. Participants in the study included 34 twelfth-grade students from Public High School 1 Palangka Raya. The validity of the instrument was evaluated using Aiken's index with input from five expert validators, while its quality was analyzed through the Rasch Model. The findings indicate that the instrument demonstrates unidimensionality, with a Raw Variance Explained by Measures value of 43.2%, confirming its effectiveness in assessing the desired aspects of science literacy. Out of the 16 items analyzed, 13 were considered fitting. The instrument also showed exceptionally high reliability, boasting a Cronbach's Alpha value of 0.89, and most items exhibited no gender bias, according to the Differential Item Functioning (DIF) test. This instrument's development is anticipated to assist students in connecting scientific concepts to real-world scenarios, enhance their science literacy skills, and raise awareness of the importance of environmental conservation, particularly regarding peatland preservation in Palangka Raya.Penelitian ini bertujuan untuk mengembangkan instrumen evaluasi literasi sains terintegrasi lingkungan pada materi termodinamika untuk siswa SMA. Metode dalam penelitian ini adalah R&D dengan model 4-D. Partisipan penelitian terdiri dari 34 siswa kelas XII-2 SMAN 1 Palangka Raya. Validitas ahli diukur menggunakan indeks Aiken's dengan lima validator ahli, sedangkan kualitas instrumen dianalisis menggunakan Rasch Model. Hasil penelitian menunjukkan instrumen bersifat unidimensional dengan nilai Raw Variance Explained by Measures sebesar 43,2%, yang berarti instrumen mampu mengukur aspek literasi sains sesuai yang diharapkan. Dari 16 butir soal yang dianalisis, 13 soal dinyatakan fit. Instrumen memiliki tingkat reliabel sangat tinggi dengan nilai Cronbach's Alpha 0,89, serta sebagian besar soal tidak menunjukkan bias gender berdasarkan uji Differential Item Function (DIF). Pengembangan instrumen ini diharapkan dapat membantu siswa menghubungkan konsep sains dengan kehidupan sehari-hari, meningkatkan keterampilan literassi sains, serta menumbuhkan kesadaran terhadap pentingnya pelestarian lingkungan, khususnya lahan gambut di Palangka Raya.