Abstract: The purpose of this study is to determine the validity, effectiveness, and practicality of learning tools to improve student’s critical thinking skills by using an advanced organizer learning model on colloidal material. The test was conducted in grade XI-5 of 7th Senior High School of Surabaya with 24 students. The learning device development model in this study uses the 4D model from Thiagarajan, but only 3 stages are applied (define, design, develop).