PENGEMBANGAN INSTRUMENT PENILAIAN AFEKTIF BERBASIS KARAKTER MENGGUNAKAN APLIKASI SURVEY MARS PADA MATA PELAJARAN BAHASA INDONESIA DI KELAS V SD/MINIM.: 23204081005M. MuhlisauthorThis study aims to: (1) analyze the characteristics of character-based affective assessment instruments using the mars survey application in Indonesian language subjects in grade V SD/MI; (2) determine the product quality of character-based affective assessment instruments using the mars survey application in Indonesian language subjects in grade V SD/MI; and (3) analyze the effectiveness of characterbased affective assessment instrument products using Mars survey application in Indonesian language subjects in grade V SD/MI. This research uses the ADDIE development model, which consists of five stages, namely Analysis, Design, Development, Implementation, and Evaluation. The research subjects included three instrument expert validators, teachers and grade V students of SD Negeri Depok 1. Research data consists of two types, namely qualitative and quantitative data. Qualitative data was obtained through observation, documentation and questionnaires. Meanwhile, quantitative data was obtained from the results of filling out the assessment questionnaire and aimed to determine the quality of the empirically developed instruments, including the level of validity and reliability of the instruments with the help of IBM SPSS 26 software. The results of the development of this character-based affective assessment tool are suitable for use with the results of instrument expert validation showing that the product is "Valid with Revision", with validation results from V1 instrument experts with 100% scroll (category "very interesting"), validation of V2 instrument experts with a score of 90.4% (category "very interesting"), V3 instrument expert with a score of 88.96 (category "very interesting"), to the overall value of the three instrument expert validators with the average value of each indicator ranging from 90.93% to 95.8%, The validity test shows 35 valid statements due to the calculation of the > rtable, and the reliability test of the Cronbach Alpha value > the value of a reliability coefficient of 0.7, then the affective assessment instrument based on the character is reliable. Thus, the character-based affective assessment instrument developed is effectively used as a tool to assess students' affective domains such as attitudes, interests, self-concept, intentions and morals.370. 114 Pendidikan Moral, Pendidikan Karakter2026-05-25UIN SUNAN KALIJAGA YOGYAKARTA;FAKULTAS ILMU TARBIYAH DAN KEGURUANThesis