Recently, problem-based learning has been used pervasively from K-12 to higher education to improve students\' learning and higher-order thinking. However, there are some limitations for teachers in planning and implementing PBL units. Therefore, the purpose of the study is to examine the characteristics of PBL and limitations of the PBL when it is implemented at the fields. Then successful e-PBL programs would be investigated to consider those as alternative ways to overcome the limitations of PBL. Through detailed investigation of e-PBL programs in both science and social science, e-PBL components of improving higher-order thinking and effective scaffolding to support students and teachers were discussed.
key words: problem-based learning, e-PBL, alien rescue, persistence in history