This type of research uses research and development (R&D). This study aims to :
1) explain the stages of developing STEM-based teaching materials on the theme
of life events to strengthen critical thinking skills; 2) analyzing the feasibility of
STEM-based life events theme teaching materials to strengthen critical thinking
skills; 3) Analyzing the effectiveness of STEM-based life events theme teaching
materials for strengthening critical thinking skills. The material developed in this
teaching material is the properties of objects. The stages of research and
development in the field of education use the ADDIE model (Analyze, Design,
Develop, Implement, and Evaluate). Data analysis techniques were carried out
quantitatively and qualitatively. Data collection techniques in the form of tests and
nontes. Data collection uses test questions, interviews, teacher and student
questionnaires and teaching material validation questionnaires. The feasibility of
using science, technology, engineering, and mathematics (STEM)-based teaching
materials can be seen from the validation results, namely: validation of test
questions 89.17%, material validation 89%. The results of the educator's response
were 94%, the responses of the students were 92%. While effectiveness is measured
based on the results of the Independent Samples T-Test that there is a difference
between the average value of the control class of 67.50 and the experimental class
of 85.21. STEM-based teaching materials can not only be used in research subjects,
but can be used as a learning resource and reference for schools. STEM-based
teaching materials present material that is in accordance with the development of
science and technology so that educators can use it to improve students' critical
thinking skills to the maximum according to learning objectives.