There was no difference between the two groups regarding the highest and lowest score for virtual learning quality. However, there were differences in each the details of each dimension. The score of online learning quality assessed by the learner and trainer is a relatively acceptable level except for learner-instructor interaction, which achieved the most excellent satisfaction among study participants. In contrast with our research findings, Iravani et al. found students' negative attitudes toward the e-learning approach during the COVID-19 pandemic, particularly in learner-instructor interaction and course evaluation (
19). In another study, the influencing factors on e-learning quality were classified into four categories of culture; infrastructure (appropriate content, both the trainees' and trainers' capability to use electronic teaching platforms); process (teaching, evaluation, monitoring, support, and learner-instructor interaction); and output (planning for improvement). This study estimated the overall condition of e-learning at a moderate level (
20). In a study conducted at the Kermanshah University of Medical Sciences during the COVID-19 pandemic, students evaluated their instructors at a moderate level and recommended teacher empowerment to develop their competencies in effective teaching methods and communication skills (
20). By surveying similar studies in different countries, it was tried to provide a general overview of the state of the quality of virtual education in different environmental contexts. For example, in a study conducted at a private medical and dentistry school in Pakistan, students' viewpoints regarding the quality of e-learning during the COVID-19 pandemic were evaluated. Study findings revealed a moderate satisfaction level with the teaching approach's flexibility and efficiency. Students were pleased with easy access to educational materials and believed virtual education was more reliable and could increase their interest. Considering that the under-study university was for-profit, the quality of students' e-learning experience was more likely to be assessed at a higher level due to a more robust socio-economic background and relatively adequate infrastructure for virtual learning (
21). These studies highlight the influential role of educational context and environmental factors in promoting e-learning (
22). Developed countries face fewer problems implementing virtual education due to the desired speed and quality of internet connection (
23). In addition, in these countries, justice in education has better conditions, and students have adequate access to information technology infrastructures and the internet to benefit from educational opportunities (
21). In a similar study by Elzainy et al., an advanced online education was promoted to be used in the problem-based learning (PBL) approach during the COVID-19 pandemic, which proved more effective than face-to-face teaching classes (
24). As a result of the review of existing literature, it has been concluded that establishing reliable and valid educational performance measurements, facilitating learner-instructor interaction, applying effective instructional methods, and ensuring that trainers and trainees are properly trained to utilize electronic resources are the best ways to improve the quality of virtual education. Therefore, objective standards are needed to ensure the quality of e-learning (
25).
Several studies have investigated the challenges of e-learning in Iranian universities. Lack of effective communication between instructors and trainees; technical and infrastructural problems; divergence between the number of educational courses and the volume of contents; dissatisfaction with the quality of contents, online exams, and assignments; delayed feedback given to learners; lack of simulation of teaching content with face-to-face classes; and accumulation of a considerable volume of teaching content around the exam time were among the potential causes of dissatisfaction with the virtual teaching approach (
21-
27). Therefore, researchers in medical education proposed several strategies to resolve the issues. They emphasized that having information about the lesson objectives and evaluation methods at the beginning of the course and having a logical sequence in teaching and curriculum content aligned with learning objectives can lead to overall quality improvement for the training process (
23). In a study by Maatuk et al. entitled "the COVID-19 pandemic and e-learning: Challenges and opportunities from the perspective of students and instructors", trainers believed that e-learning could develop students' technological skills. However, it might cause some challenges, particularly regarding inappropriate electronic infrastructure and lack of financial support. In this study, students declared their positive attitude toward the effects of e-learning and agreed on its potential impact on improved academic standards. Despite mentioned advantages, such as reduced costs, flexibility, and innovative learning approaches, they believed that one of the significant downsides of e-learning was imposed pressure on learning activities. This study revealed that the country's low-quality internet services were a significant challenge that required significant financial resources (
28). Thus, it is essential to consider many recommendations from similar studies to overcome existing challenges. The provision of internet services to students and faculty members, establishing up-to-date electronic libraries with adequate devices, constant attention to information technology infrastructure, and periodic maintenance of computers and supporting equipment are among the necessary programs which should be taken into action to provide e-learning services properly (
28). Studies in other countries have found this helpful training for community health workers. Among the studies conducted in Rwanda, virtual training for community health workers with a lower literacy level has increased the speed of teaching and learning them. They recognized this training as a continuous, cheap, and easy-to-use model for community health workers (
29).
Compared to other studies, the current research depicts a more appropriate state of online learning from the viewpoints of trainees and instructors. This condition might be because of various reasons, such as a suitable student-teacher ratio in Behvarz education centers in Iran and more accessible learner-instructor interactions during the COVID-19 pandemic. A combined education was implemented in these centers, and the face-to-face training approach was still the dominant strategy to provide educational materials regarding practical sessions; higher satisfaction levels were observed regarding the quality of virtual education among the study participants. The shorter length of education and less complexity of scientific topics in the educational courses of Behvarz training and using more educational videos for the practical learning of trainees were, among other probable reasons, for a higher level of satisfaction.
Moving from traditional teaching methods to online methods can create opportunities for educational quality improvement. However, in order to resolve existing challenges, it is recommended to limit the size of online classes to facilitate prompt feedback to learners, consider an appropriate type of instructional design in line with study objectives, and mention new roles for instructors as site facilitators and non-traditional trainers in the distance learning process. Providing a continuous evaluation of students through standard quality indicators and promoting a well-established online environment can increase the appropriateness of study courses. A limitation of this study is that we cannot generalize the results to other centers. In addition, different participants' previous experiences with online education can affect our results. Because of the interchangeability between distance education types, it was difficult to compare this study with other research. However, we tried to consider the standard dimensions of this education in our study. In our research environment, online learning has been used.