University of Isfahan New Educational Approaches   2423-6780 13 2 2019 02 20 When is Problem-based Learning More Effective? A Meta- analysis When is Problem-based Learning More Effective? A Meta- analysis 77 94 24009 10.22108/nea.2019.105216.1104 FA Amene Aali Assistant Professor, Allame Tabatabaee University, Tehran. Iran 0000-0002-1713-4158 Ali Khorami M.A. in Elementary Education, Allame Tabatabaee University, Tehran. Iran S Eslami M.A. in Elementary Education, Allame Tabatabaee University, Tehran. Iran Journal Article 2017 07 16 Problem-based Learning as an active and constructive teaching method in the educational system, drew the attention of researchers in recent decades and many studies have been conducted to evaluate its effectiveness that have reported mixed results. Therefore, this meta-analysis was performed in order to achieve more accurate judgement about the effectiveness of PBL. The study population included all studies that has been conducted since 1384 which measured the effect of PBL on student performance that are available in databases.  The evaluation is based on inclusion and exclusion criteria, 27 studies were selected and were analyzed using the software CMA2. By performing the sensitivity analysis in order to remove biased published studies, 73 effect sizes remained. The combination effect sizes of fixed and random models are 774/0 and 723/0. This means that PBL is moderately effective. Based on the analysis of moderator variables revealed that PBL is more effective on skills, in university classroom and compared to traditional methods. Problem-based Learning as an active and constructive teaching method in the educational system, drew the attention of researchers in recent decades and many studies have been conducted to evaluate its effectiveness that have reported mixed results. Therefore, this meta-analysis was performed in order to achieve more accurate judgement about the effectiveness of PBL. The study population included all studies that has been conducted since 1384 which measured the effect of PBL on student performance that are available in databases.  The evaluation is based on inclusion and exclusion criteria, 27 studies were selected and were analyzed using the software CMA2. By performing the sensitivity analysis in order to remove biased published studies, 73 effect sizes remained. The combination effect sizes of fixed and random models are 774/0 and 723/0. This means that PBL is moderately effective. Based on the analysis of moderator variables revealed that PBL is more effective on skills, in university classroom and compared to traditional methods. https://nea.ui.ac.ir/article_24009_c546ae9a5e07cd1caaf41c9f0d3bbe85.pdf