Azimah, W., Hendrayana, A., Fatah, A. 2020. The Effect of Modified Cognitive... Matematika dan Pembelajaran, 8(2), 112 of 121 This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. THE EFFECT OF MODIFIED COGNITIVE LOAD THEORY PROBLEM BASED LEARNING MODELS TO PROBLEM SOLVING STUDENTS IN CILEGON Wafa Azimah 1 , Aan Hendrayana 2 , Abdul Fatah 3 1,2,3 Mathematics Education, University of Sultan Ageng Tirtayasa, Indonesia wafa.azimah@gmail.com Abstract The aim of this study is to determine the effect of the modified Problem Based Learning Model with Cognitive Load Theory to students problem solving abilities. This research was conducted in SMP Negeri 1 Cilegon in the academic year 2019/2020 with the sample used was class of VII A as an experimental class using CLT-modified PBL models and class of VII E as a control class that gained learning with the usual PBL models. The research method used in this study is a mix methods of the concurrent embedded model with quantitative methods as the primary method and qualitative as a secondary method. The results and discussion of the study showed that the achievement and improvement of the problem solving ability of the experimental class was better than the control class. So it can be concluded that there is a positive influence on CLT modified PBL models on students' problem solving abilities. In addition, the amount of cognitive load possessed by students while learning can be one of the main factors that can affect students' problem solving abilities. It is believed that reducing extraneous cognitive load can improve students' problem solving abilities. Keywords: Problem Solving; Problem Based Learning; Cognitive Load Theory. Citation: Azimah, W., Hendrayana, A., Fatah, A. 2020. The Effect of Modified Cognitive Load Theory Problem Based Learning Models To Problem Solving Students In Cilegon. Matematika dan Pembelajaran, 8(2), 112-121. DOI: http://dx.doi.org/10.33477/mp.v8i2.1366 INTRODUCTION One effort to improve the quality of education is through learning mathematics. Mathematics is a subject that has an important role as a medium or an appropriate tool in achieving student competence. But in practice, learning mathematics is still often considered negative as a scary learning so that not many students are interested in learning mathematics well and mastering the material. The Program for International Student Assessment (PISA) in 2018 states the results that Indonesia's mathematical ability is ranked 72 out of 78 countries, including level 1 with a score of 329 points from an average score of 489 points (OECD, 2019). The ISSN 2303-0992 ISSN online 2621-3176 Matematika dan Pembelajaran Volume 8, No. 2, December 2020, p. 112-121.