Problem-Based Learning (PBL) has been implemented in the official curriculum in Korea since the 1990s, after being introduced to medical schools in the 1980s as a new method that overcame the weakness of the subject-centered curriculum [1,2]. The University of Ulsan medical school became the first medical school in Korea to implement PBL in its official curriculum for second-year students in 1991, while Sungkyunkwan University School of Medicine is Korea’s only school that provides PBL curriculum for all first and second year courses starting from 1998. According to a survey conducted in 1999, 15 schools (37.5%) have implemented PBL, and 13 schools were scheduled to implement it [1]. the Korean Medical Education Report showed that 38 schools (95%) were implementing it [3]. Many schools are currently continuing to operate PBL, but some have not yet introduced it while others have suspended its implementation.

Although PBL has been implemented in many medical schools as a new learning method for several years, there has so far been a lack of nationwide researches to analyze and summarize the trends of PBL through a specific investigation into its current status. In terms of an overall investigation into PBL, the Research Group of PBL Tutorial (RGPT) conducted a “nationwide study on the status of PBL” in 1998, at a time when PBL started to be introduced in Korea [1]; and in the study on the status of education for the Korean Medical Education Report in 2013 [3], only a simple survey regarding PBL was carried out. As this survey was focused on identifying formal aspects such as whether to implement PBL, the implementation period, credit provision and PBL room, it was impossible to grasp in detail how the PBL courses were run. The lack of well-organized research results has made it difficult to understand the operation methods of other schools. In addition, schools that want to adopt PBL or other schools that want to know how to manage PBL in order to improve their PBL program often have to contact every single school that uses PBL.

For this reason, there is a need to identify the detailed current status of the overall operation, such as PBL operation mode, tutor participation and role, class environment, placement of lectures, assessment method, PBL efficacy, and obstacle factors. Now that it has been approximately 20 years since PBL was introduced in Korea, this study aimed to investigate the current status of PBL and analyze the current state of operation PBL in Korean medical schools.

According to the results, 35 of the 40 Korean medical schools (87.5%) that responded to the questionnaire were confirmed as implementing PBL. In a study of the status of PBL in several Asian countries, it was found that PBL was being implemented in over 90% of medical schools in Japan [5], 50% to 70% of medical schools in Indonesia [6], and 100% of medical schools in Taiwan: a total of 12 schools [7]. Considering this, the status of PBL implementation in Korea is similar to that of other Asian countries.

The analysis on the introduction period shows that 27 of the 35 schools (77.1%) introduced PBL in Korea from 1999 to the mid-2000s. This is consistent with the findings of the study conducted by Servant [6] who reported that there was explosive growth in the introduction of PBL by medical schools from 1990 to the early 2000s. In consideration of this, it can be concluded that Korean medical schools have tried to grasp the trend of global medical education and adapt to its changes.

The reason why medical schools in Korea introduced PBL can be attributed to changes in the educational philosophy of the educational institutions themselves, but this study evaluates the effect of medical school accreditation as one of the major causes. Similarly, in her study of PBL status in Asian medical schools, Servant [6] also evaluated that one of the factors influencing the proliferation of PBL in Asia was each government’s demand for the reform of medical education. According to the analysis, as a result of each government’s request, schools reorganized their own curricula and introduced new teaching methods such as PBL [6]. As in Asian universities, the rate of use of non-lecture classes in the medical curriculum has been selected as evaluation criteria for medical school accreditation in Korea, and for this reason, each university has adopted PBL as a matter of policy to meet such criteria. In other words, it was evaluated that each medical school worked to introduce PBL as one of the non-lecture learning modalities to improve on the traditional lecture-centered curriculum. Considering this situation, the researchers expect that medical schools in Korea will continue to increase a number of their non-lecture classes, including PBL.

In terms of the position of PBL in the curriculum of Korean medical schools, 30 of the 35 schools added PBL to the traditional lecture-centered curriculum, a model referred to as “hybrid” PBL, combining traditional lectures and PBL. This tendency was similar to other Asian schools. According to a study by Servant [6], most of the Asian schools have adopted a hybrid PBL curriculum. With regard to why hybrid PBL is being widely operated in Korea medical schools, this study analyzes that there are three reasons: First, professors try to convey as much knowledge as possible during class time, thinking that what the professor has not taught the students in class will not be learned. In other words, because they perceive the most effective means of transmitting knowledge as “lectures”, they are worried that if lectures are reduced and PBL classes are increased, students will not acquire sufficient medical knowledge. Second, professors point out that there may be some inaccurate knowledge among the contents that students learn through PBL discussion. Citing the concern that students collect data from unreliable blogs on Internet instead of referring to verified medical literature, PBL tutors are concerned that the information students bring up during discussions or submit as assignments may be not accurate medical knowledge. In other words, professors tend not to trust in the accuracy and depth of the knowledge students learn through PBL. In that sense, professors who view PBL with skepticism consider lectures as the most reliable way to acquire accurate medical knowledge from an expert. This is interpreted as consistent with the result of opinion of professors giving the lowest score to the “in-depth learning” survey question related to the effectiveness of PBL. Third, some professors say that the process of discussion among students during PBL is a waste of time. Professors think that students can acquire knowledge easily and quickly through lectures. In the PBL, however, students have to gather for a few hours to gather the same knowledge they can get from the lecture, and this discussion sometimes goes in the wrong direction. Professors will negatively view a series of learning processes through the PBL. The researchers estimate that such professors and schools with negative stance on PBL will hesitate to introduce a PBL-oriented curriculum.

Through analyzing the factors that inhibit the effects of PBL, the following two points were noted: First, students felt uncomfortable with discussion in PBL. In particular, students tended to be cautious about expressing their opinion in front of a tutor who has authority. They were also reluctant to speak in class unless they were completely sure of something, because they sometimes get negative feedback when they say the wrong thing in class. This leads to a learning climate in which it is better to stay still than to speak incorrectly, which also hinders active discussion. In fact, tutors point out that students tend to talk less when learning topics in PBL that had not been dealt with previously in a lecture than when learning topics that had already been taught in a lecture, because in the former case they are dealing with a lot of information that they do not know. Second, students said they felt uncomfortable contradicting or criticizing other students’ views. They were worried that such criticism might hurt other students’ feelings because they are peers who have to share much time during lectures, PBL courses, and clerkship until graduation. In that sense, the researchers interpret that such a cultural climate can influence the activeness of discussion during a PBL course.

In relation to this, a study by Mahbubani [8] pointed out that the cultural climate of Asian countries could affect the PBL class. In his study, he argued that students from Asian universities were passive because of their cultural backgrounds, making PBL difficult and, in extreme cases, PBL impossible. Hofstede [9] describes the distance of the power of each country in numerical terms by explaining how the weak accept the inequality as the norm. The figures in Asia are generally higher than those in Europe or the United States, suggesting that Asia is a more authoritarian society. The cultural differences could be one of the reasons why Korean students have a somewhat passive attitude in the PBL discussion [9]. However, while acknowledging that cultural characteristics play a role, Khoo [10] insisted that the characteristics found in PBL at Asian medical schools, such as passive discussion participation, are likely a phenomenon that will be limited to the beginning of its implementation, and if the class atmosphere changes, even Asian students can be expected to actively join in PBL discussion. We agree with opinion of Khoo [10]. The changed learning atmosphere is highly likely to lead Korean medical school students to involve themselves in PBL discussion. Indeed, during PBL training at an overseas medical school, we witnessed Korean students actively participating in the discussion and enjoying PBL without the pressure of the test.

PBL and traditional curriculum have different student evaluation systems. In other words, students are evaluated as pass or fail in the PBL, and ranked by grades in the traditional curriculum. Therefore, if the existing curriculum and the PBL curriculum are competing, students are likely to consider PBL section of the curriculum to be optional time as the conventional course is already too demanding [11]. Students are expected to want tutors to act as a facilitator rather than an evaluator. The authors suggest that in order to create a safe atmosphere, the tutor should be present in class but minimize their intervention. Yeo and Chang [4] reported that according to a survey of student preference regarding the presence of a tutor in PBL class, students did not want authoritative tutors but considered the presence of a tutor was helpful in creating an academic atmosphere. A study by Chung et al. [12] also showed that 59.5% of students did not want their tutors to intervene in discussion, and wanted them only to make final comments. Khoo [10] proposed a method of conducting class without tutors. The results of such studies imply that creating a safe academic atmosphere is necessary for active discussion.

In addition, it was confirmed again that faculty development and tutor training and case development are the tasks that should be prioritized to successfully implement PBL. As for the many schools which have implemented hybrid PBL, different tutors are assigned according to the group, and tutors change every time cases change. Whenever the tutor changes, the class proceeds could also change. Thus, many students often feel confused about the progress of the class, and tutors also worry about how to lead the class when they undertake PBL for the first time or deal with cases irrelevant to their major. In addition, such difficulties have not yet been sufficiently resolved because even if the tutor training is performed, the attendance rate of the tutor is low. Therefore, the researchers suggest as a solution that tutor education videos be produced and shared via e-mail, and a PBL online library is made so that such videos are available at any time if necessary.

In terms of case development, there were difficulties in developing a good case suitable for PBL class because individual schools had little experience in case development. To address this, the researchers suggest that the schools, which have difficulty in developing cases, download and utilize the cases in the PBL Case Bank which has been developed and operated by the Korean Society of Medical Education RGPT. The PBL Case Bank is a web-based data bank which provides this service in order to encourage medical schools to upload the cases they have developed and allow member schools to download and use accumulated cases free of charge. It is easy to find useful cases, because cases can be searched by diagnosis name and clinical department. However, it is necessary to download the applicable case and convert it into the PBL form which is suitable for each school, considering that the forms each university uses when it develops cases are different.

In addition, it is noted that there are schools that present PBL materials in the form of videos, simulated patients and other materials. rather than papers. We evaluate that this change suggests that PBL can be connected with CP curriculum. In other words, it would be meaningful to suggest a new integrated learning model of presenting PBL cases in the form of videos or simulated patients, learning the relevant CP, and then learning the relevant clinical skills.

The significance of this study can be evaluated largely in terms of two points. First, it identified the operation status of PBL in all medical schools on a national basis. Now that many schools, which have implemented PBL or are trying to introduce it, are wondering how PBL is being run in other schools, this study may be of great significance in that it can help each school address questions by providing detailed data in relation to the current status of PBL courses implemented in all medical schools since the 1990s. Second, this study could be useful in that it suggested the results of of survey on the various operating methods which schools can choose as their PBL operation method; problems in the implementation of PBL; and directions for improvement. The results of this study will be able to be used as a useful tool for school trying to introduce or improve PBL and to determine the appropriate approach to PBL.