In the present study, the application of the TBL method was compared to the lecture method in the teaching of a medical physics course in the students with poor performance. The classification of these students was based on the comparison of the mean score of each student in the prior semesters with the average of all the students in the class, the outcome of which was considered statistically significant (P = 0.005).
According to our findings, the TBL method could enhance the learning level of the students. All the participants could pass the medical physics course, and based on this analysis, the satisfaction of the students also increased significantly. Furthermore, more than 90% of the students believed that TBL was more effective in learning than the lecture method as it encouraged their participation in the learning process. This is consistent with the previous studies in this regard (
5,
20,
21). For instance, Akbari et al. (
22) reported that the mean scores of the students who participated in a TBL-based class at a rehabilitation clinic were higher compared to the mean scores of the control group. In addition, 97% of the students in the mentioned study agreed to partake in the course and considered TBL to be useful in the passing of the course. In another research, Vaezie et al. (
23) compared TBL and lecture in the teaching-learning process of nursing students, reporting that the satisfaction and mean score of the general tests based on the TBL method were higher compared to the lecture group. In the study by Kumar et al., the majority of students believed that the TBL method helped in the conceptual learning of the course and effectively increased their knowledge and understanding of the concept.
In the present study, TBL resulted in the high satisfaction rate of the students and a significant increase in the grades of the medical physics course over the lecture method. Moreover, all the students could successfully pass the course, which indicated the increased academic efficiency in the medical physics course and higher satisfaction of those who initially had not considered the medical physics course as specialized and necessary. Consequently, the total mean score of the students all the courses was higher compared to the medical students admitted in 2016 and 2017 (P = 0.005).
Few studies have been focused on the impact of TBL on students with poor performance. In a research in this regard, Koles et al. (
24) reported that students in the lowest academic quartile may benefit more than other students from the TBL strategy. Yet, mastery of course content enhanced in Medical students’ higher performance (
24). If the impact of TBL on the reduction of number of failures could influence the poor performance of students, the results obtained by Brunner et al. confirmed the effectiveness of the method in improving the poor performance of the students (
25). Indeed, the mentioned research confirmed the impact of TBL on poorly-qualified students.
The results of paired t-test test showed no significant correlation between the previous grade of each student and the scores obtained in the TBL-based course (P = 0.497) (
Figure 1). In other words, no association was observed between the previous grades of the students and their current scores in the medical physics course. Therefore, it could be concluded that TBL could easily influence the performance of weaker students in terms of curriculum. Therefore, the students with lower and higher scores in the medical physics course could not be distinguished based on their average score in the entire previous semester within the range of 12.3 - 17.0, and further investigations on larger sample sizes are required in this regard.
In response to the question “Did the teacher’s skills and mastery influence the choice of the most appropriate method?”, 52.4% of the students selected the TBL method, while 19% considered no difference in this regard. In the current research, the teacher had several years of experience in the teaching of the course by lecture, and this was his first experience of TBL implementation. The reason behind the responses of the students was possibly rooted in deeper learning and better transfer of the educational content (
26) as in the TBL methodology, the students may have associated the method with the skill and mastery of the teacher. Notably, 90% of the students believed that the presentation of the medical physics course by the TBL method was more appropriate, and 85% believed that the students are interested in participation in the learning process through TBL, which may support the veracity of their statements.
As can be seen in
Figure 2, the average trend of the TBL tests was incremental, and the average grades of the class improved with time, so that the GEE showed a significant increase in the grades, especially in the last two tests compared to the initial tests. These findings were predictable due to the familiarity of the students with the new presentation method (i.e., TBL) although they had not previously experienced TBL in any other courses. One of the reasons behind the incremental score pattern could be the notification of the results of the individual TBL tests since 2 - 3 days after the test, the individual test results of the communication group of the class were labeled from the highest to the lowest in the form of an Excel file. The scores of the student seemed to have prompted them to upgrade their status to the top or maintain their favorable status.
Due to other midterm exams of the classes, the TBL test was not given in one of the sessions, and the volume of test pages doubled for the following exam, totaling 16 questions and 40 pages of the reference books instead of the usual 20 pages. After passing the test, the majority of the students acknowledged that the large volume of the educational material caused a decline in their mastery of the content and difficulty in studying the textbook.
Figure 2 shows the effects of the increased volume of the contents in a visible drop in the eighth test. Therefore, it could be concluded that the selection of the appropriate amount of educational contents in the TBL method must be heeded by teachers.
The assessment of the scores of all the students in the medical physics course with the TBL method indicated a significant increase in the scores as measured by
t-test compared to the lecture method, which had been used for the same students the previous year (P < 0.01). Our findings in this regard are consistent with several studies (
20,
21,
27).
The main limitations of the present study were the small sample size and quantitative statistical volume of Qom University of Medical Sciences, which made it quite difficult to generalize the results to other groups and communities. Another notable point about the improve scores of the students was the possible interference of the new method (TBL) with the previous learning method (lecture), because they were not unable to pass the medical physics course in the past semesters. This study was carried out with the knowledge of these limitations since the primary aim of the study was to increase the active participation and dissatisfaction of students with poor classroom performance. Achieving this goal could improve the performance of students (
10,
11,
28,
29).
The main strength of the study was the uniformity of some features with possible effects on the study outcomes, such as the curriculum content, teacher, and especially the study group.
5.1. Conclusions
According to the results, the implementation of TBL in the medical physics course could enhance learning motivation, increase satisfaction, and improve the mean scores of the students with poor performance. Furthermore, the students found TBL to be a more relevant learning method in demanding mathematics-based courses, which resulted in greater participation by more students in the learning process.