Pedagogical Challenges in Online Teaching: A Qualitative Study on Vietnamese University Teachers of Social Sciences

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I. INTRODUCTION
The application of online teaching platforms in teaching and learning has become popular in higher education institutions (HEIs), especially following the Covid-19 pandemic.Before the pandemic, many traditional faculty members were unfamiliar with online teaching and lacked proper training to teach online effectively (Gülbahar & Adnan, 2020).Due to the university closure to halt the spread of coronavirus (Carrillo & Flores, 2020;Gillis & Krull, 2020;Lei & So, 2021), many teachers were compelled to shift from face-to-face to virtual classes, even if they were not well prepared (Cutri et al., 2020;Cutri & Mena, 2020) to ensure students' learning progress.In a short time, online teaching became more familiar to many educational institutions and faculties and has been applied explosively due to the pandemic (Koksal, 2020;Villaumbrosia, 2020).The pandemic is identified as a driving factor which forced land-based learning to be replaced by online learning, at least during the lockdown (Lei & So, 2021;Li & Lalani, 2020).Vietnamese higher education is not an exception (Ho et al., 2021;Pham & Ho, 2020).

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 228  Before the Covid-19 pandemic, online teaching in Vietnam was employed mainly in the context of distance education, which has been established and developed in some HEIs since the 1990s.In Vietnam, distance learning was previously referred to as e-learning (Pham & Ho, 2020).The first two Vietnamese HEIs to implement e-learning were Ho Chi Minh City Open University and Hanoi Open University, established in the early 1990s.Up to now, more universities have been allowed to develop e-learning programs.The applications of e-learning in Vietnam's HEIs are classified into two types: distance training programs provided by two Open Universities and some other institutions and the combination of e-learning with traditional campus-based programs piloted in a small number of universities (Le et al., 2021).According to the Vietnam Ministry of Education and Training (MOET) (2017), several different teaching approaches are applied in distance education, such as teaching through radio and television, paperbased materials sent by post, online materials, and a combination of the above methods.
Over the past three decades, distance learning has significantly contributed to developing human resources for mountainous, highland, remote and island areas in Vietnam.Nevertheless, E-learning still holds a modest position, in terms of legally recognised programs and numbers of students, compared to traditional campus-based programs in Vietnamese HEIs (Pham & Ho, 2020).In 237 universities and academies across the country, excluding ones belonging to the National Security and Defence sector, out of more than 1.6 million undergraduate students, only 39,600 students were enrolled in distance learning in the 2019-2020 school year (MOET, 2021a).Moreover, the utilization of educational technology and the optimization of the advantages of distance teaching is still hindered due to a lack of willingness and legal foundation that allow HEIs to incorporate educational technology into formal courses systematically (Ho et al., 2021;Pham & Ho, 2020).
In May 2021, MOET issued a circular, allowing eligible universities to teach online up to 30% of undergraduate training programs (MOET, 2021b).Online teaching is no longer merely temporary in response to the social distancing caused by the Covid-19 epidemic.Vietnam's HEIs have acknowledged online teaching as an indispensable trend and have taken advantage of its benefits.The initial foundations of distance education over the three decades in Vietnam, the forced situation posed by the pandemic, and the legal advance have all paved the way for a stronger development of this training mode.It is predicted that the demand for online teaching and learning is projected to continue to rise quickly in the future and eventually become an inevitable trend (Cutri & Mena, 2020) thanks to its undeniable benefits and opportunities (Adedoyin & Soykan, 2020;Appana, 2008;Haq, 2021).
Although there are positive and impactful influences from social and policy contexts, the intricacies of online teaching necessitate additional examination.By focusing on the current status of online teaching during its period of growth and changes, this article especially delves into the challenges of pedagogical practices in HEIs.Drawing from a dataset comprising interviews with teaching staff from both public and private universities, the primary investigation of this article seeks to answer the question: "What pedagogical challenges has the teaching staff of social sciences in Vietnam's HEIs faced during the implementation of online teaching?"By shedding light on these challenges, this article aims to contribute insights to the ongoing discourse on online teaching in higher education and provide potential avenues for addressing these issues.

Concepts of online teaching
Literature shows a wide array of concepts of online teaching, namely online education, online learning, remote teaching, and distance learning.These terms can be used interchangeably.In essence, online teaching is a process of developing educational resources, delivering teaching, and managing an educational programme using the internet and technological platforms for teaching and learning (Adedoyin & Soykan, 2020;Fry, 2001).This means that the interaction between instructors and learners, and among learners are physically distant; accordingly, communication and information transmission are mediated by compatible technological devices and platforms (Aguilera-Hermida, 2020).Hrastinski (2008) differentiates two types of online learning: asynchronous and synchronous.Our article focuses on the synchronous approach of teaching in the online environment, which requires instructors and learners to be engaged in the process of instruction in real-time and live virtual classrooms.

Online teaching in practices
Basically, online teaching requires all the essential elements of instruction, including curriculum, pedagogy, roles, competencies, interactions, and assessment (Adedoyin & Soykan, 2020).Researchers also show that a well-planned  229  online education program greatly differs from "emergency remote teaching" to respond to a pandemic or disaster (Hodges et al., 2020).Noticeably, it should not be misunderstood that online teaching is simply a digital transformation in higher education because it is only one of the characteristics of digital transformation (Adedoyin & Soykan, 2020).It has been experienced for years before the Covid-19 pandemic (García-Morales et al., 2021;Marks et al., 2021) and expedited by the pandemic (Adedoyin & Soykan, 2020).
Previous studies show that online teaching during the Covid-19 pandemic presented many difficulties and challenges for learners, teachers, and institutions.From the students' perspective, Aguilera-Hermida (2020) points out three categories of challenges.The first one is situational and environmental challenges driven by various distractions such as family members, noise, housework, and financial hardship during the pandemic.The second is online educational challenges, namely, difficulties in understanding the learning materials and loss of internships or clinical practices, insufficient supporting resources to complete schoolwork, difficulties in communicating with teachers, lacking internet connection, decreased quality of the learning process, and stress due to an increased workload.The last is the emotional difficulties, such as deficient motivation and negative emotions, stress, anxiety, worry about getting infected by the coronavirus, and mental health issues.However, from another perspective, for example, Inkaew (2022) shows that learners are also aware that online learning has both advantages and disadvantages and with the necessary efforts, learners acquire the required knowledge and skills.
However, the transition from face-to-face teaching to online teaching brings many potential prospects for different stakeholders.Some beneficial points for individuals include taking advantage of available resources (Schleicher, 2020), saving time or spending more time with their families (Edelhauser & Lupu-Dima, 2020), achieving personal improvement in technology skills (Aguilera-Hermida, 2020), actively arranging learning or working schedules (Schleicher, 2020).Using technology is an excellent chance for educational institutions to promote deep understanding and better meet the needs of learners (Schleicher, 2020).In addition, e-learning offers many other advantages, such as comprehensive coverage, cost-effectiveness, uniformity, fast teaching and learning, and rapid economic development through e-commerce (Oyediran et al., 2020).
The literature review reveals that the challenges and opportunities associated with contemporary online teaching are multifaceted and intricate, depending on the unique characteristics of a given country and locality.Literature reviews show that applying online teaching and learning can be "a double-edged sword", which brings both benefits and challenges for teachers and learners (Lucas & Vicente, 2023).However, there is a lack of a specific and detailed analysis of the pedagogical challenges and hindrances of online teaching in social sciences.Therefore, this article aims to fill this research gap and offer valuable significance in supplementing the broader picture of online teaching nationally and internationally.

MATERIALS AND METHODS
This study uses a qualitative research method with a semi-structured in-depth interview, snowball sampling (Creswell, 2013), and a thematic coding analysis (Robson & McCartan, 2016).

Data collection
A semi-structured interview (Edwards & Holland, 2013;Robson & McCartan, 2016) was applied to explore the experiences and practices from the teachers' perspectives.The interview guide (Patton, 2015) focuses on teachers' and faculty deans' opinions of online teaching and learning, challenges that arose from the sudden shift from on-site to online teaching, and actions and efforts made to adapt to this transition personally and institutionally.
A purposeful sampling strategy (Creswell, 2013), which used criteria and snowball techniques, was applied to reach the information-rich participants during the data collection process.The interview criteria include the type of university (private and public, financially autonomous and fully supported by the government), disciplines (social sciences and humanities), genders, ages, years of teaching experience, and working positions.It should be clarified that in many cases, the researchers could not reach the participants via working emails that are not publicly available on university websites.For this reason, snowball sampling (Robson & McCartan, 2016, p. 281) was a reasonable and practical strategy.Using the snowball strategy, the researchers first interviewed several university teachers from professional networking who met established criteria.These teachers were then used as key informants to refer the researchers to other teacher participants who were also interviewed and utilised as informants.This process was repeated in a snowball effect, thereby facilitating an increasing number of respondents and potentially enhancing their willingness to share valuable information.The sampling process was terminated as the researchers reached the saturation point (Merriam & Tisdell, 2016, p. 101,109), where they were no longer gaining new insights from the interview questions.
Via Google Meet, the research data was collected through real-time online interviews with 23 university teachers from July to September 2021.The duration of the interviews, on average, was approximately one hour.The participants' areas of expertise are social sciences and humanities and range across different fields, including Cultural Studies and Anthropology, Vietnamese Studies, Asian Studies, Sociology, Education, Vietnamese Literature, English as a Foreign Language, Tourism, Philosophy, Psychology, Business Finance, and Law.The participants were currently working at nine universities (three private universities (A, D, I), three public universities receiving financial support from the host unit or MOET (C, F, H), and three public universities with financial autonomy (B, E, G)) located in Ho Chi Minh City, where the most severe pandemic occurred in Vietnam at the time of conducting this study.Most interviewees are university teachers with master's degrees; two-thirds of interviewees are female; the average age is 42 years old, and they have an average of 15 years of teaching experience (Table 1).

Private universities 9
During the interviews, the researchers encouraged the participants to talk about their own experiences, difficulties, and challenges in their online teaching.Note-taking was employed simultaneously.All of the interviews were recorded with the consent of the teachers.Continuously and concurrently, the recording data was transcribed verbally.Weekly, the research team conducted a meeting to review the key findings that were uncovered during the data collection process.To ensure the anonymity of the interviewees, the interview audio recordings are entirely deleted

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 231  after transcribing.The names of interviewees and their workplaces are also changed using pseudonyms or common nouns with ordinal numbers, for example, Teacher 01, University A. The transcripts were imported to MAXQDA analytical software for data analysis.

Data analysis
The interviewed data were analyzed with the thematic coding method (Robson & McCartan, 2016).It was not time-consuming for the researchers to get familiar with the whole data corpus and catch the general and initial ideas of the data, thanks to their working closely together and regularly discussing the notes taken after each interview.The coding process began with some predetermined codes (p.468), originating in the literature review and research question.However, many new codes emerged while the researchers dealt with the data.The coding segments extracted were given code names based on their meanings.After finishing the initial coding step, the code system was thoroughly reviewed and applicably adjusted before being themed into categories.Finally, a thematic map was constructed by grouping themes "based on content or theoretical grounds" (p.476).The study encompasses a variety of themes that are beyond the scope of a single article.Therefore, this article focuses exclusively on one central theme: the pedagogical challenges in online teaching practices.The findings section provides a detailed examination of this aspect.
The researchers have working experience in various environments, such as research institutes, public and private universities.These different backgrounds partly help them understand the organizational structure and the context of the current online teaching in Vietnam.However, it also affects the interpretation and evaluation of research data and findings.Thus, to overcome this well-recognised subjective limitation, the researchers cross-check with each other after each coding step and manuscript for more objectivity and constructiveness.

Lecture preparation
Regardless of age and years of teaching experience, many of the teachers in our study agreed that the shift from traditional face-to-face to online teaching created many challenges in their lesson preparation.The interviews revealed that the digitisation of lectures means teachers had to spend more time (re)designing their lesson plans more thoroughly.Instead of using textbooks, PowerPoints, and blackboards, they had to find ways to convey teaching contents effectively, hoping to maintain students' attention and concentration on their online lectures.
Depending on the characteristics of each subject and discipline, the pressure of preparing lesson plans varies among university teachers.For example, according to Teacher 12, lecturing in the study program of Hospitality and Restaurant Management requires hands-on demonstrations that enable students to learn specific professional skills.Online teaching forces teachers to produce simulating videos that are time-consuming and require more videomaking skills, while their expectations of imparting content cannot be effectively met.In other cases of more theoretical disciplines, such as Sociology and Vietnamese Literature, teachers had to invest much effort into their lesson plans to stimulate students' engagement and interaction.Teacher 11 disclosed: I have to make a lot of effort in online rather than on-site teaching.I have to choose content, input data, and ways to deliver lectures and control the class.It requires me to be more proactive and ask more open-ended questions to train students to think and interact.If teachers can create many interactive situations and raise issues for students to discuss or argue with, it means success.Sitting in front of the computer and just talking and talking will be very boring.I am terrified of that, so I have to pay much more attention to online classes (Teacher 11,Pos. 38).
Some others, like Teachers 05, 14 and 18, reported that it took more time to prepare different teaching materials and select different sources to share on their screens.In addition, those who had to be in charge of various subjects concurrently in a semester often faced a deficiency of time to design their lessons thoughtfully and meticulously (as stated by Teacher 13, working at a public university).It should be noted that teaching staff are supposed to complete a certain teaching load prescribed by MOET or their governing bodies.This is a kind of organizationally exerted pressure that rises not only in online but also in face-to-face teaching activities.

Lecture delivery
Limitations in the teaching methods According to the interviewees, it was more challenging for teachers to transfer knowledge and illustrate specific skills in online classes than in face-to-face ones.For example, in a class on communication science, the teacher found it almost impossible to invite students to act out and practise problem-solving skills in sales situations (Teacher 12); in a class on hotel-restaurant services, it was impossible to personally demonstrate how to arrange party dining tables (Teacher 18).In law classes, mock trials were not conducted in a normal atmosphere (Teacher 03).Foreign language teachers could not correct students precisely as they do in face-to-face classes (Teacher 05).In another case, Teacher 21, specialising in Experimental Psychology, had to delay the laboratory experiment session.Although online teaching in her university (University H) is only a temporary solution during the intense outbreak of Covid-19, it reveals some limitations of this teaching mode.
Instead of teaching and learning with all the senses, an audio-visual approach via live online teaching is one of the primary forms of transferring knowledge from teachers to students.Students' group activities in online classes are often reduced or cut off due to the limited time and large class size.For example, in a literature class, students could not theatricalise a literary work together, which makes the lesson more alive and stimulating and gives students a chance to reveal and demonstrate their talents (Teacher 04).Communication in this kind of classroom is mainly listening verbally and delivering the lectures.As mentioned in this article, the inadequate instructor-learner and peerpeer interaction, lack of group collaboration activities, and inefficient forms of knowledge transmission vividly and visually are considered disadvantages of online teaching.Accordingly, most teachers used a lecture-based approach in their online classes.Below is an exciting illustration by Teacher 12, an expert in Sustainable Tourism, about "talk the hind legs off a donkey" to avoid the "downtime" caused by the lack of learner interactions: Online teaching requires teachers to read a lot, and this helps them speak without interruptions and pauses.My university's regulation is that an online learning period is only two-thirds the length of face-to-face learning.That's enough.Actually, the content I teach is much more than what I might teach in a face-to-face class.I often ask questions and then answer them myself because many students do not have the habit of studying online and are pretty passive.Teachers have to read a lot and prepare themselves well to talk the hind legs off a donkey (Teacher 12, Pos.78).
While some teachers tended to provide students with more knowledge than expected, others likely itemized their teaching contents to basic main points, slowed down the teaching speed, and gave more details to ensure students fully grasped their lessons (Teachers 01 and 14).This also leads to more talk and explanation.
Although the lecture-based approach was mainly employed, the way the teacher interviewees delivered online lectures compared to face-to-face courses is quite noticeable.Some who specialize in Sociology and Literature discerned their pedagogical freedom in knowledge transfer.In traditional classroom-based lecturing, it is more flexible in delivering lectures without or less being monitored, interfered and disrupted, whereas teachers have to use a more selective, cautious form of expression in terms of words and illustrative examples.The justification is that online lectures are often recorded and backed up on the universities' LMS for students to review when needed.The universities' inspectors also regularly participated in these online classes to observe the teaching and learning process.Therefore, more carefulness in speech was found in online classes.

Limited learner-teacher and learner-learner interaction
Most interviewees stated that the essence of teaching involves two-way communication between teachers and learners, as well as among learners.Undoubtedly, communication takes place in face-to-face classes both verbally and through body language (eye contact, gestures, actions, smiles, and so forth), enabling coordination and reactions to occur more smoothly and continuously.However, these teachers asserted that interpersonal communication was "limited", "absent", "lacking", and "short on human emotions" in live virtual classrooms.The limitation in the interaction between teachers and students is displayed in the fact that the students' feedback and interactions were significantly reduced, about 70%, although the teachers had to talk more (Teacher 18).
Most teachers did not choose group activities for online teaching because it became less interactive, and teachers would talk more, for example, giving more examples and explaining more.Due to the ineffective interaction, I needed to talk more and repeatedly ask, "Can you hear me well?" or "Do you understand this?"I have to ask such questions over and over again, which is time-consuming.Moreover, I had to sit for a long time.Whereas, teaching in an onsite class means that I can go back and forth to one to another group, stand up and sit down comfortably" (Teacher 01, Pos.22).

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 233  Team working (group discussion, debate, and evaluation) and individual exchange activities were reduced due to internal and external factors, such as the unstable internet connection, lack of students' concentration, and limitations in classroom management, especially in classes for general subjects and normal programmes.It should be noted that there are basically two types of courses in many Vietnamese universities.In contrast to normal courses, the so-called "high-quality" programmes are primarily provided in English by high-quality Vietnamese and international lecturers or experts, following international high-standard curricula and syllabi with high learning outcomes requirements, small class sizes and extremely high tuition fees.
The interviewees' description of the interaction in the online classroom shows the absence of human interaction: "a true monologue" (Teacher 02), "monologue" (Teacher 17), "asking questions and answering them myself" (Teacher 12), "it is like I am sitting in front of a laptop, talking to myself" (Teacher 14), "like interacting with a box", "like talking on the phone" (Teacher 07), "talking to the machine" (Teacher 01), "sitting and talking to the machine without seeing the student" (Teacher 12).As a result, teachers were under much pressure to maintain class continuity, eliminate "dead time" (Teacher 01), "downtime" (Teacher 12), or avoid creating it due to a lack of face-to-face interaction.
I have encountered a huge challenge, that is about the method.Because students had more anonymity, they all turned off the cameras, mute the microphones, and did not even have a serious learning attitude.(Teacher 02,Pos. 20) Although fully aware of this lack of interaction and working for improvement, the teachers confessed that they had to "leave many students out" (Teachers 02 and 03).That means they cannot maintain and create a learning atmosphere that stimulates all students' dynamic engagement during class.On the other hand, the lack of productive interaction caused negative effects on their teaching enthusiasm, as described namely: "teaching motivation decreased" (Teachers 03, 08, 12), "enthusiasm decreased" (Teacher 14), "suppressed", "tired", "uncomfortable" (Teacher 07), "annoyed", "a lot of pressure", "stressful" (Teacher 12), and "irritated" (Teacher 18).
Although the research data does not mention it much, there is a noticeable absence of peer-to-peer interaction and connection between classmates, which are crucial elements for creating a positive and dynamic learning environment.
In face-to-face learning, students will have new friendships in the university environment, but in online learning, they are completely separated; each person has his/her own laptop, sitting in one room in a different locality.It cannot create tight interactions and connections between students (Teacher 14, Pos.130).
The online classroom presents a major challenge due to the absence of consistent human interactions, resulting in a significant decrease in the level of interaction.This poses difficulties in terms of teaching motivation, as previously mentioned, and also in terms of teaching methods, which will be further analyzed in the following sections.

Students' inattentiveness and passivity in learning
One of the substantial obstacles that the teacher interviewees faced in online classes is their learners' low concentration.In the virtual space, which is inherently anonymous and lacks physical presence, many students log in and/or take attendance at the beginning of the class without intensive participation.According to Teachers 11 and 17, students might sit in front of the screen but mind their personal things (eating, watching movies, watching YouTube, playing games, and so on) or even completely leave the online classroom (for their chores or sleeping).
When I checked students' names at the beginning of the class, they often said 'yes', but when I asked questions during the class, they gave no response.They also did not submit their homework; they simply disappeared.That means they only joined the class for attendance checking.So, they did not listen to the whole lecture.They entirely lost attention and submitted no assignment as requested (Teacher 17,Pos. 78).
In addition to the distraction of students during the class, their inactive participation and inappropriate online learning methods are another challenge for teachers to ensure an online class takes place as expected.
The biggest challenge is students' inactivity because they just waited until the class begins, opened their computers, and joined the class.They did not participate actively and read the materials beforehand.The main subjective factor is their inertia.They do not have the habit of searching for additional information or finding suitable learning methods for themselves (Teacher 14,Pos. 238).

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Along with the individual students' learning attitudes are the external factors, such as a lack of a suitable physical learning environment, especially a quiet study space, causing them to lose concentration.This impacts the atmosphere and quality of an online learning class to some extent.
Many students' family environments are not suitable for learning online.For example, in my class, a student had to study while helping with household chores and selling groceries.When he turned on the camera, what we saw on the screen was that his house was really crowded; customers were buying goods, his parents were shouting, and his siblings were in a mess.It means that the student's privacy was exposed to the whole class.Some parents did car repairs at home.My goodness, all of these were streaming.When students unmuted their microphones, it was very noisy; when they opened the cameras, we could see how busy their houses were (Teacher 18,Pos. 355).
It is challenging for the teachers to maintain students' presence and engagement compared to the face-to-face learning environment.Firstly, the challenge came from the limited possibility of managing the students' actual attendance in the classroom, even though several different checking measures for attendance were applied at the different phases of the class, for example, using the school email to sign in and so on.Secondly, it was difficult for the teachers to maintain the students' concentration, especially in large-sized classrooms and those with low learning motivation.
Teaching a large-sized class also takes more time.For on-site classes, when students feel bored, they will talk loudly.If I pause for a moment, students look at my facial expressions, they will understand and stop talking.However, in online teaching, if I stop, they may think I am going somewhere and ignore me (Teacher 14, Pos.62).
Consequently, this requires teachers to have some skills to attract students' attention, displayed in the lesson designs and plans as mentioned above.Simultaneously, they have to talk more to reduce silent moments.
I always had to call students A, B, and C, asked them to prepare an answer for some certain questions, and asked if they had seen the exact page of the book.I had to attract their attention and kept reminding them over and over.Obviously, I got tired because of talking a lot.For example, "I have one question, who can answer it?"I called one student, and then jumped to others (Teacher 07, Pos.43).
Concurrently, besides the primary platform for teaching (Microsoft Team, Zoom, Google Meeting), the teachers were required to stay connected with their students through multi-platforms, for instance, Zalo -a kind of Vietnamese social network, and the LMS provided by their universities.Multi-tasking to capture student presence and participation hinders the teachers from entirely focusing on their lectures.

Student assessment
The assessment of learning is an essential element in the teaching and learning process of higher education.In the early stage of the sudden shift from face-to-face to online teaching under the force of the Covid-19 pandemic, it was disorienting for many faculty members of some universities, such as Private University D and Public University H, to implement online examinations.As a consequence, their final examinations were postponed (Teacher 18).Ensuring the objectivity, honesty, and authenticity of online testing is the bottleneck that confuses many faculties in the first semester of full-time online teaching.
In my English pronunciation class, I tried to allow students to do phonetic transcription.But both working individually and in a group were not suitable.Why? Students copied and pasted, so they had many similar mistakes.With a large-sized class of 40 students, I had to work hard to score all the individual exercises.So, I let them work in teams of 5-6 students.Then I could not know who actually worked and contributed to the assignment and who didn't, and whether a team copied the answers of another.Actually, I cannot see and check my students' work directly.Such are the limitations of online examinations, which even experienced teachers still worry about (Teacher 05, Pos.25).
Evidently, it is challenging to select appropriate forms of online exams to ensure teaching and learning quality.For example, some teachers believed that a multiple-choice exam was not an excellent option to avoid cheating, an oral examination was unsuitable for a large-sized class, and high-quality results of online exams partly depended on students' self-discipline and honesty.Therefore, some teachers affirmed that students' online test results are not highly qualified.
As being well acknowledged, online teaching during the pandemic has presented numerous challenges in comparison to traditional face-to-face instruction.These challenges include interruptions in internet connection,

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 235  difficulties in organizing teaching activities, and so on.Many interviewed teachers expressed that these limitations in the online learning environment notably impacted the quality of teaching and learning.Designing an appropriate approach to assess students' learning properly has become a significant challenge.As a result, some universities, for example, University G and University A, have opted for a less stringent approach to assessing student outcomes.Some teachers described what was happening in their universities as follows: The exam questions were not too difficult, mainly following the syllabus.I taught a general subject for nonspecialist students, so the content was mainly in the textbook.I also made both easy and difficult questions but made sure that students could do the test.As long as students had a good learning attitude and studied well, they got good grades (Teacher 19,Pos. 101).
Regarding test scores in online teaching, if students failed too many subjects, they would sue.That is the general situation.Students would react and plead that because they studied online, they failed the tests, which affected their total learning outcomes.Therefore, it is often seen that the test results are not objective.This is a reality that anyone working in education understands.The actual quality of online learning was limited and relatively low (Lecturer 13, Pos.59).
Online teaching during the pandemic has hindered the assessment process for learners.Challenges include delays in assessment progress, selecting appropriate assessment forms, maintaining ethics and honesty among learners, and ensuring fairness in recognition of results and quality of learning outcomes.

The ineffectiveness of online teaching
The teacher interviews revealed the inefficiencies of online classes reflected in three aspects: inability to capture the classroom circumstance accurately, difficulty in grasping students' knowledge acquisition, and prolonged lecturing.
Firstly, the teachers' coverage and support for learning activities in online classes are diminished.It is especially troublesome to manage online discussions in classes sized 100-200 students, which is reported in Teachers 14's classes in Sociology and Teacher 16's classes in Education Management at Public University H.However, it should be emphasized that, even in face-to-face classes, teachers face a similar problem.Therefore, this is not due to online teaching in essence, but it is rooted in the university system, as mentioned in the first finding section of this article.Compared to face-to-face teaching, teachers cannot easily observe and grasp students' group discussions in a live virtual class simultaneously.They can only attend and observe one discussion room at a time for several minutes.Therefore, it is impossible for them to adjust and support their student groups when needed timely.Therefore, the inability to accurately capture the classroom's circumstances to support students and make immediate adjustments is one of the major limitations of online classrooms.Almost half of the faculty members in our study confirmed this.
When teaching face to face, with just a glance, I can know how my students are doing, which student is able to answer or be confused about my questions, and whether they are focusing on my lesson or daydreaming.I can see them with my eyes and intuitions.However, I can not do it through the camera (Teacher 07, Pos.37).
They also faced difficulty in grasping students' levels of knowledge acquisition.Even after receiving the students' confirmation about understanding through careful discussion and question-answer, they still affirmed that their lesson acquisition was not as expected, which was reflected in the results of the students' examinations (Teachers 01, 09, 14).In addition, they hardly knew how much the students were interested in the given lectures, and how suitable their teaching methods and content flow and implementation were.These situations may lead to untimely adjustments in the online teaching process (Teachers 11,12,and 21).
After lecturing, I am not completely sure whether the students understand or not.I have often asked the whole class if they understood, and they were completely silent (Teacher 14, Pos.248).
Secondly, the inefficiency manifests itself in the fact that the duration of an online learning session can be lengthened depending on students' knowledge acquisition and discussion abilities.When teachers decided to maintain group discussions in large-sized online classes, the possibility of overtime often occurred (Teachers 14 and 16).In addition, the duration of the online teaching session was often drawn-out when teachers had to give more detailed instructions to ensure that all students acquired the lectures well, for example, in Teacher 21's Psychology class.

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Discussion
This article explores the pedagogical difficulties that social science teachers in Vietnamese HEIs encounter while implementing online teaching.The study draws on interviews with teaching staff from public and private universities located in Ho Chi Minh City.The findings reveal numerous pedagogical challenges, including lesson plan preparation, teacher-student interaction, teaching approaches, student involvement, assessment, and overall effectiveness.Notably, these obstacles primarily stem from external factors rather than individual motivations and beliefs.
The study offers further discussion on these issues.Firstly, university teachers encounter difficulties when it comes to executing teaching practices and effectively delivering lecture content.Replicating on-site activities in an online setting is not always viable, which creates a challenge in terms of teaching approaches.The integration of classroom-based and online teaching, also known as blended learning, is a feasible and efficient pedagogical method for addressing the challenge of teaching subjects or skills which cannot be taught entirely virtually (Govindarajan & Srivastava, 2020;Neborsky et al., 2020).Additionally, pedagogical autonomy is crucial to optimize the benefits and effectiveness of online teaching in the context of the digital transition of higher education, as argued by Røe et al. (2022).It allows teachers to choose appropriate teaching strategies and contribute to long-term curriculum development.
Secondly, students' passive learning involvement is one of the difficulties teachers face in online teaching.According to Tran (2013), the passive learning style prevalent in Vietnamese universities can be attributed to the inadequacy of physical, spatial, and technical infrastructure necessary to promote independent and active learning.Furthermore, students are not adequately trained to become proactive learners.The persistence of teacher-centric and antiquated pedagogy contributes to perpetuating passive learning among students.This situation can be attributed to the scarcity of qualified pedagogical expertise and the limited time for teachers to invest in refining their lectures and enhancing their professional skills.The root causes for this predicament include the low salary policies and the ongoing shortage of academic staff, which force university teachers to take on more teaching responsibilities across multiple institutions or engage in supplementary employment to sustain their livelihoods.On the other hand, it is criticized for the lack of acknowledgement from universities to encourage reform and initiatives in instructional methods, the lack of impenetrable barriers, and precise warning mechanisms from the governing bodies and HEIs towards negligence and teaching quality.Consequently, these elements create a vicious circle that results in learners' lack of initiative and creativity in learning.Tran's analysis provides valuable insights into understanding the passive learning style of students in an online environment.Aligning with the finding of Pham et al. (2021), our study has revealed that to foster students' engagement and participation in virtual classrooms, instructors must adopt multiple roles, which causes distraction during their lectures.
Thirdly, students' learning assessment is identified as one of the pedagogical challenges.Although there have been timely instructions from MOET on online teaching in Vietnam's HEIs during the Covid-19 pandemic (MOET, 2020), this superficially formal guideline, which lacks clear implementation criteria, has created great difficulties for the HEIs and their teachers in the quality assessment of online teaching.
One limitation of the study is its research approach, specifically the use of snowball sampling.This nonprobability sample reduces the representativeness; accordingly, the findings cannot be generalized to the whole population.However, it is important to note that qualitative research primarily focuses on exploring and understanding the meaning individuals or groups ascribe to a particular social or human problem, not on testing objective theories by examining the relationship among variables.Despite this limitation, the study's findings are valuable and can provide insights into the teachers' experiences and perspectives.The generalizability in this qualitative research can be applied in terms of the reader of this study, where the reader "decides whether the findings can apply to his or her particular situation" (Merriam & Tisdell, 2016, p. 256).
For further research, we suggest a thorough investigation into online teaching strategies in higher education, both institutional and pedagogical aspects.This could involve examining how teachers adapt to institutional changes in policies related to online and hybrid instruction and exploring the variations in teachers' preparation and online teaching implementation among different types of universities.Furthermore, teachers' subjectivity, such as their ethics and beliefs in online teaching, should be further investigated.Education is an institution in which teachers have an important role in knowledge production and transmission; therefore, teachers' ethics and beliefs are believed to

Table 1 .
Demographic profile of the research participants