Applying Flipped Classroom Model: A Case Study in Teaching English for Academic Purposes at International School, Vietnam National University Hanoi

Nguyen Thi Thu Huyen

Department of Applied Linguistics, International School, Vietnam National University, Hanoi

ABSTRAT: Flipped classroom, or inverted classroom is a teaching approach in which new content can be learned at home with the support of digital materials sent by teachers and homework can be done in class through discussion and group work activities. This mode of teaching has been being implemented quite widely in the world, but it has only been paid a lot of attention in Vietnam recently. The present study investigates the application of flipped classroom model in teaching English for Academic purposes (EAP) for undergraduate students at International School, Vietnam National University (IS-VNU). An action research to implement flipped classroom model in teaching EAP was carried out in a class of 21 sophomores at VNU-IS. Findings indicate that there is an improvement in class time management and VNU-IS students’ involvement in EAP educational process. Besides, based on results of questionnaires and observation, students and teacher alike have the positive perceptions of flipped learning applied in EAP course. It is therefore concluded that flipped classroom mode will possibly be a complementary method in delivering EAP lessons at IS-VNU. The study also points out some recommendations for better implementation of flipped classroom in further researches.

 KEYWORDS: Flipped classroom, flipped classroom application, action research, EAP course

1. INTRODUCTION

Since the existence of education system, traditional teaching and learning method in which teachers give lectures, students write down the new knowledge and try to remember it, do some practice then do homework at home has been practiced. However, in current era, with the fast-paced development of technology, face-to-face teaching method needs to be combined with technology-based one. Flipped classroom is one of the pedagogical approaches in which technology is utilized to support student’s cognitive development. This teaching and learning approach inverted the traditional classroom concepts (Drake, 2016). In flipped classroom, the learning processed is reversed in the way that students explore the new lessons with the aid of video lectures or related material uploaded by teachers, and they spend most of the class hours interacting with lecturers and peers on any issue of the lectures they cannot comprehend at home. Apart from videos, before going to class, students of FC mode can use any digital devices to help them understand the core contents of the lessons. In FC model, teachers are considered to be an instructor who has the key role of leading as well as holding the activities so that the students’ skills can be improve by employing particular techniques like self-studying, lesson preparing at home and getting ready for discussion inside the classroom (Aljaraideh, 2019).

EAP courses are regarded as a contrast to general English ones. The focus of EAP courses is more on reading and writing while that of general English language courses is on speaking and listening. In terms of formality, EAP courses are prone to be more formal, academic than general English courses.

Gillett and Wray (2006) considered EAP to be a practical branch of ELT in which “the role of the EAP lecturer is to find out what the students need, what they have to do in their academic courses (target need), and help them to do this better in the time available.” As EAP courses usually focus on reading and writing, the long reading passages and difficult writing lessons can be a boredom to students. As observed by an EAP teacher, student’s level of regular attention decline because the EAP lectures “rife with theory is often too much for students to absorb” (Nguyen, 2021, p. 149). Nguyen (2021) also claimed that the teaching time is insufficient for the teachers to cover all the core contents for students, and students cannot have enough time to practice or discuss the topics fully. Moreover, EAP lessons are generally delivered in traditional method, which cannot increase students’ engagement during class time. There is a need for a new teaching method which can motivate students in learning EAP. FC model seems to be an answer since students can get to know the new content in advance by reading the course book or watching the video lectures. Hence, class time is mainly allocated to practice or discussion, which can boost student’s interaction with classmates and teachers. At International School, Hanoi National University, EAP is an obligatory course for nearly every major. Therefore, this article aims to investigate the implementation of FC model in teaching EAP at IS-VNU, then examines its impacts on students’ performance mainly based on qualitative analysis.

1. LITERATURE REVIEW

2.1. Concept of flipped classroom

FC is regarded as a quite new concept in the field of education which draws attention of quite a lot of researchers to investigate and employ its pedagogical features. Zhang et al. (2017) in his study gives the definition of FC as the flipping of the teaching process. In traditional class, the teacher deliver lesson, and students attempt to understand the new information in class. Then at home they will do self-practice to get progress themselves. As stated by Zhou et al. (2017), “the so-called flipped classroom” is to reverse the traditional classroom and convert the educational mode from “inside” classroom into “outside” the classroom. In a flipped classroom setting, students engage with new topics through pre-class materials like videos or online coursework provided by teachers, reserving in-class time for deeper interaction with educators through discussions and active participation. Within the flipped classroom model, there’s an enhancement in the interaction between instructors and students, allowing instructors to utilize lecture time for practical applications. Similarly, Angeliki et al. (2017) approach the flipped classroom model as a restructuring of the educational process, swapping traditional learning methods between school and home, thereby empowering students, promoting autonomy, and integrating ICT. This restructuring often leads to partial adoption of distance or blended learning (Angeliki, Spyros & Evangelia, 2017). Kandroudi & Bratitsis (2013) also see the flipped classroom as a form of blended learning, where students consume lecture content at home and engage in classroom discussions and activities during class time. This shift aims to foster active learning and boost engagement by redistributing the roles of lecture delivery and homework completion, transferring lectures to home and activities to the classroom (Alavi, Keyvanpanah & Fazl Ali, 2016; Rezaei Fard, Z., Shahrokhi, M., Talebinezhad, M., 2022). Bergmann and Sams (2014) highlight additional features of the flipped classroom, such as self-paced learning, which accommodates individual differences and addresses the absence of instructors or students through supplementary resources like videos or multimedia provided by instructors.

2.2. Four pillars of flipped classroom

Hamdan et al. (2013) sought to illuminate the elements of the FC model by dissecting the acronym FLIPPED. They elucidated that F denotes a “flexible environment,” L signifies a “learning culture,” I represents “intentional content,” the first P stands for “professional educators,” the second P denotes “progressive networking activities,” E translates to an “engaging and effective learning experience,” and D encapsulates a “diversified and seamless learning platform.”

Building upon Hamdan’s framework, Pearson’s School Achievement Services identified four foundational aspects, or “pillars,” of the FC model: Flexible Environment, Learning Culture, Intentional Content, and Professional Educator.

• F, representing “Flexible Environment,” entails teachers creating adaptable settings for students to choose when and where they study. Additionally, teachers in the FC model can physically reconfigure classroom spaces to accommodate various lesson objectives, allowing for individual, paired, or group work. They also display flexibility regarding class timelines and student assessments.
• L, standing for “Learning Culture,” signifies a profound shift in the educational atmosphere. Unlike traditional classrooms where teachers serve as the sole source of information and students passively absorb knowledge, the FC model places students at the center of learning, transforming them from recipients to active participants.
• I, representing “Intentional Content,” involves FC teachers curating digital materials for independent student study at home and selecting content for direct classroom instruction. This deliberate selection allows educators to adopt student-centered approaches and implement active learning strategies during class time.
• P, denoting “Professional Educator,” underscores the pivotal role of teachers in facilitating FC. They decide when and how to transition from traditional classroom activities to personalized student learning at home, maximizing class time for meaningful teacher-student interaction.

Fig. 1: Four pillars of FC (adapted from Hamdan et al., 2013)

According to Gojak (2012), FC educators should not dwell on whether to flip the classroom but rather on optimizing class time usage. They are tasked with ongoing observation and careful assessment of student performance, rendering their role more demanding and significant compared to traditional teaching methods (Noora, 2013).

2.3. Procedure of implementing flipped classroom

Estes et al. (2014) proposed a three-step process for implementing the flipped classroom model, comprising the pre-class, in-class, and post-class stages.

Top of Form

Bottom of Form

Fig. 2: Procedure of implementing FC (adapted from Estes et al., 2014)

In the first stage (pre class) students study basic content at home by means of online platform. English teachers at universities prepare and send or upload the video-lectures to students. They can use Shub, Canva or Microsoft teams, Google classroom platform to perform these tasks. English students can watch these videos as many times as possible, so they can concentrate on any matters of concern “at their own space and their own pace” (Strayer, 2007). Thus, according to Hertz (2012) in these two stages, students have increasing opportunity to interact with the educational material in comparison with the time when they learn the lectures in class (Hertz, 2012).

In the middle stage (in-class stage) English language students are supposed to use the knowledge and information they acquire outside classroom to discuss or take part in other interactive activities with their classmates. This stage takes place in physical classroom in which teacher apply active and participatory teaching techniques. In this stage of FC model students are asked to interact with their peers in a way to show that they have become “active users of information, based on their personal experiences, opportunities, critical thinking and interaction through group activities” (Bergmann et al., 2011).

In the last stage, after students take part in FC activities in English class, they can refer back to the platforms. As claimed by Estes et al. (2012), students can watch the videos again from different perspective, identify any possible weakness they have, or widen their knowledge.

In order to implement these three stages, teachers need to ensure the following principles recommended by Kim, Kim, Khera, and Getman (2014, p. 67). The first principle is that instructors provide the opportunity for students to gain preliminary information before the class activity. Second, instructor encourage students to watch online lectures and to be prepared before the class activity. Third, teachers organize assessment methods; Fourth, teachers link in-class activities with out – of – class activities. Fifth, teachers give unambiguous and well- organized instruction to students. Sixth, teachers supply students with enough time for completing the assignments. Seventh, teachers encourage students to build a learning community. Eighth, teachers give immediate feedback on individual or group work activities; and lastly, teachers provide students with the use of familiar technologies that they can access easily.

III.  METHODOLOGY

3.1. Setting and participants of the study:

3.1.1. Setting of the study

IS is a school belonging to VNU, in which students are required to study their majors entirely in English. EAP is one of the required courses for first year students. The aims of this course are to help students to become a more capable writer, reader and thinker with two main sections: reading and writing. The reading passages in the reading section are on the social and academic topics, but they are rather long ranging from 700-1200 words. The writing section cover important yet quite hard themes like plagiarism, citation, summarizing, paraphrasing, quoting, etc.

EAP is a four-credit course, designed for students of nearly every major at IS-VNU such as International Business, Accounting and Auditing, Business data analysis, Management of information technology, etc. The course lasts 15 weeks (equivalent to one semester) and has the mid-term test (in which students are asked to present the reading passages in the Reading section) and the final test (in which students are required to write an assignment related to the themes learned in Writing section). In order to be eligible for EAP course at IS, students must have acquired B2 certificate in English or other equivalent ones.

3.1.2. Participants of the study

21 students in one random EAP Class at IS-VNU took part in the study. The demographic survey revealed information about them: 42% of the participants is male, 52% is female and the rest belongs to LGBT group. All the participants between the ages of 19 and 20 are sophomores who come from various towns in the northern part of the country, with 57.1% residing in urban areas. Their average GPA in the first year ranges from 2.8 to 3.45. Among the participants, 61.9% have been learning English for 5-10 years, 28.5% have been exposed to English for more than 10 years and 9.6% have been studying English for less than 5 years.

3.2. Action research

3.2.1. Steps in action research

An action research is conducted to implement FC model in EAP course in class ACF2022A in the first semester of academic year 2023-2024 at IS-VNU. The case was studied to investigate the feasibility of applying the FC model in EAP course at IS.

Microsoft teams was used as the educational platform in order to implement FC mode in EAP class. Since the Covid-19 Pandemic, each student at IS-VNU have been provided with a Microsoft Teams account. Microsoft Teams is considered to be tailored for educational purposes, equipped with integrated AI features, and it can serve as a potent communication application for educational institutions, fostering improved collaboration and learning experiences (Microsoft.com). Microsoft teams was employed to upload the learning materials in pre-class step of FC model.

Fig. 3: Action research steps (adapted by I N Gita and R A Apsari, 2018)

The action research was developed in a circle including 4 steps: planning, acting and observing reflecting.

In the initial step (Planning), the researcher prepared a face-to-face meeting with students as well as creating a questionnaire to seek for students’ perception of FC model application. In the second step (Implementation) the research facilitates group discussions and presents the discussion outcomes to the class, and draws conclusions. Throughout the Implementation phase, the researcher observes the application of FC model, especially student’s participation and activity during the teaching and learning process. The third stage is Observation, which involves assessing students’ responses to the given questionnaires. In the fourth stage (Reflection) the researcher evaluates students’ challenges in grasping the EAP lesson content in FC model and how feasible it is to apply FC model in EAP class.

3.2.2. Implementation of FC model in EAP class

In the first week of the course, the researcher explained to the students about applying FC mode in their EAP course. Efforts were undertaken to clarify to students the integration of traditional classroom instruction with remote learning through computer-based activities, using Microsoft Teams. For the students who were not familiar to this platform, the research took time to instruct them how to use it. Moreover, students were informed that this process in the FC model is “reversed” by that of the conventional one, in which the new lesson content would be studied at home and class time would be used for questions and discussion. Also, students were explicitly informed that the objective of this approach was not to assess their individual performance but rather to evaluate the effectiveness of the flipped classroom methodology. Therefore, it was crucial for them to provide honest responses to the various questions posed, ensuring that the research could yield reliable conclusions.Top of Form

Bottom of Form

In the next 12 weeks (from week 2-week13) flipped learning was used, in which the core knowledge of the lesson was uploaded in class Microsoft teams for students to study one week before the lesson. The last two weeks (week 14 and week15) used for instructing students how to do the final assignment and were carried in the conventional method.

The lesson core content was uploaded in the “files” tab in the class teams and store in Class Material folder a week in advance for students’ home self-study, which comprises two sub-folders: videos and slides.

In the “slides” folder, students can find the main content of the next lesson, the examples to illustrate the theory provided and the keys to the question in the EAP course-books. In the “videos” folder, students can watch the video designed by various researchers, educators or teachers related to the lesson as it was recommended by Bergmann and Aaron (2012) that both creating self-produced videos and utilizing videos made by others are acceptable. Students were encouraged to thoroughly review all materials in the class material folder before coming to the class. For in-class activities, the researcher incorporated a review session to assess students’ understanding and retention of knowledge for 15-30 minutes. This review session typically consisted of a series of review questions or was in the form of quizzes (using the app quizizz.com for Writing Section or quizlet.com for Reading Section). In this review session, sometimes students were asked to present in groups how they understand the core content of the new lessons learned at home.

The figure below shows the structure of the EAP flipped class in the study.

Fig. 4: Structure of the flipped classroom

3.2.3. Instrument

Questionnaires were distributed to the participants at the end of the course to seek for their opinions of the implementation of flipped classroom. The questionnaire consists of two main parts: the first one includes the questions about student’s demographic information and the second one includes the questions on their perception of FC model applied in their EAP course. The questionnaire was adapted from that of Nguyen (2021).

The observation form was used by the teacher to take notes the key steps in the EAP lessons when FC model was utilized. The reflection form was developed on the basis of four pillars of flipped learning proposed by Hamdan et al. (2014), in which the researcher reflected on four main parts: Flexible environment, learning culture, intentional content and professional educators.

1. RESUTLS

4.1. Student’s perceptions on the application of flipped classroom in EAP class

Questionnaires were sent to participants at the end of the course to investigate their perceptions of and evaluation on FC model application in their EAP course.

Table 1: Students’ opinions on their mastery of lesson content

With regard to the students’ evaluation on the mastery of the lesson content, the mean 4.13 shows the participants believe that FC model helps them learn the core content better than conventional approach. Specifically, they can apply the knowledge of the course and acquire skills to cite the sources as well as write the referencing; paraphrase, summarize and quote the information with the mean 3.92, 4.01 respectively.

Table 2: Students’ opinions on in-class activities EAP flipped classroom

When evaluating the in-class activities, students highly appreciate the benefits of FC model applied in EAP course including having more chances to work with peers (with mean of 4.18) and more feedbacks from teachers (with mean of 3.86). The highest mean of 4.35 and the lowest standard deviation of .559 point out that students have high opinion of time management in FC approach.

Table 3: Students’ general evaluation on flipped classroom application in EAP course

The above table shows that in general, respondents show the preference of FC model to the conventional model (with the mean of 4.15) and approval of FC model application in the future (with the mean of 4.34).

4.2. Teacher’s observation and reflection on the flipped classroom implementation in EAP course

4.2.1. Teacher’s observation

The main steps (pre-class, in-class, post-class) of FC model application in EAP class at IS-VNU were observed and noted down by the researcher.

In pre-class stage, students were given the code to get access to the class Microsoft Team. They were supposed to preview the EAP materials uploaded in “file” tab of “General Channel” in Microsoft Teams before the class time. Generally, nearly all of the participants read to comprehend the slides and watch related videos at home. Some special cases were noted. One student had difficulty in getting into the platform, and the teacher supported by sending the instructional video and responding to the student’ questions. Two students faced challenges in understand the course content (related to Writing section theory in EAP course), so the teacher arrange a private talk with them to give more guidance and explanation. One who started self-study the materials but discontinued before completing was given encouragement by the teacher to fulfill the task. It was also observed that several students spent quite short time finishing the lesson while for others, it took them quite a lot of time to preview the lesson and some watched the videos again and again. So, it is noted that the pace of learning for individual student can vary, and self-study at home can help individual manage their previewing time at their own pace.

During in-class activity stage, students were observed to interact with their classmates quite actively. Students interacted with each other by asking questions, explaining ideas, offering comments, communicating, conferring, supporting, comparing, and responding, all of which enhanced their learning experience. During their presentation on EAP reading and writing topics, sometimes, however, they showed misunderstanding of some issues which later was brought up for discussion by the teacher. This discussion led students to identify errors themselves and suggest the correct options. As a result, students got more involvement in the discussion and paid attention to the key points of the lesson. Moreover, in this stage, students were put in different groups to take part in review session, in which they were expected to do quizzes with other group members (using quizziz app or quizlet app). The teacher, then gave on-site feedbacks to separate groups to make sure that all individuals could take in the core content of the lesson. Another noticeable thing in this stage is that as students have already prepared for the content of the next lesson, there was quite a lot of time in the lesson after students had finished presenting. This time was then mostly used for interaction between student-and-student as well as student-and- instructor during class hours.

In post-class stage, students went over the materials again in Microsoft Teams to have deeper understanding of the lesson or they did the review questions that they got wrong answers again to see whether they could get all right in this step or not. Students reflected on their own misunderstanding or on anything that they could not comprehend thoroughly in the previous stages and some asked the teacher for further support.

4.2.2. Teacher’s self-reflection

Teacher’s self-reflection was based on four pillars of FC model recommended by Hamdan et al. (2013): F (flexible environment), L (learning culture), I (intentional content), P (professional educators)

Regrading to flexible environment, in EAP course when applying flipped learning, students were given flexible learning modes. They were given the materials of the following lesson one week in advance, and they can choose the pace of learning, the comfortable place and convenient they at their wish. On the teacher’s side, she could use class time for organizing activities for students instead of giving the long lectures like in the traditional mode. Thus she could devote more time to assist students by answering their questions, giving them more practice or offering constructive feedbacks to individuals.

In terms of learning culture, the teaching method employed by teacher in EAP course when using FC model is student-centered. In EAP face-to-face lessons, most of the class hours were allotted for discussion, practice and interaction. Students have more opportunities to work with classmates and to receive feedbacks from teacher in FC than in conventional class. For instance, in week 5 when studying about plagiarism, students spent most of the class time to discuss in groups about how to identify the cases of plagiarism (among the situations given by teacher). They shared their viewpoint with peers, reasoning and drawing their own conclusion. They got involved in nearly every activity organized in each lesson and showed enthusiasm when cooperating with peers.

In relation to intentional content, EAP course aims to introduce students to many new concepts or long and quite complex reading passages which take them time to comprehend. By uploading the intentional materials which explains the concepts/reading passages meticulously beforehand, teacher saved class time for practice and discussion. In the traditional mode, the teacher had to use a lot of time to clarify these concepts (for Writing section) or to let students read the passages (in Reading section). On the contrary, in FC model, time was utilized for students to present their knowledge of the new lesson or discuss the lesson with friends, and utilized for teacher to answer students’ questions and provide them with feedbacks.

Concerning professional educators, teacher in EAP course applying FC model got the role of an instructor, not a lecturer. As mentioned above, class hours were mainly for students to cooperate with friends to perform the activities arranged by the teacher. During EAP lesson, the teacher went round and supplied students with instant feedbacks. Moreover, when using FC model in EAP course, the teacher took time to assist any students having trouble in pre-class and post-class, not only in class learning. As Choe & Seong (2016) stated, teacher’role in FC class was changed from “sage on the stage” to “guide on the side”.

1. CONCLUSION

Some conclusions of the study can be drawn as below. Students at IS-VNU have positive attitudes towards the implementation of FC mode in EAP course by showing strong preference to the use of this model in the future. Moreover, there is an improvement in student’s involvement in the lesson activities as well as in their interaction with classmates and teachers. Time management in EAP class hours also improved when less of it was spent on delivering the lectures but on discussion and practice. Therefore, it is concluded that applying FC model in EAP course at IS-VNU is feasible with favorable technological condition, great support of teacher and approval of students. Although FC model applied in EAP course proved to have many benefits, there exist some difficulties in the implementation regarding to platform access, student’s comprehension of the core content when previewing at home or teacher’s excessive time for preparation. It is recommended that FC model can be applied at a larger scale at IS-VNU, and in compensation for teacher’s devotion to FC preparation, lesson can be reusable and can be shared with learning and teaching community.

REFERENCES

1. Alavi M., Keyvanpanah S., Fazal Ali F.(2017). The Impact of Flipped learningon the Professional Development ofNew English Teachers: TheirOccupation and Attitudes. LinguisticResearch in Foreign Languages, 7(2),471-496
2. Aljaraideh, Y. (2019). Students’ perception of flipped classroom: A case study for private universitiesin Jordan. Journal of Technology and Science Education, 9(3), 368-377. https://doi.org/10.3926/jotse648

3. Angeliki P., Spyros P., Evangelia M. (2017, July). Implementing a flipped classroom: a case study of biology teaching in a greek high school, 18 (3).
4. Bergmann, J., & Sams, A. (2012). Flip your classroom: Reach every student in every class every day. International Society for Technology in Education.
5. Choe, E., & Seong, M-H. (2016). A case study of theflipped classroom in a Korean university
   general English course. Journal of PanPacific Association of Applied Linguistics, 20(2), 71–93.
6. Cole, J. , & Kritzer, J.  B.  (2009). Strategies for success:  Teaching an online course. Rural Special Education Quarterly, 28(4), 36-40.
7. Gillett, A & Wray, L (2006) ‘EAP and Success’ in Assessing the Effectiveness of EAP Programmes, BALEAP.
8. Drake L., Kayser M., and Jacobowitz R. (2016) “The flipped classroom. An approach to teaching and learning,” Retrievedfrom: https://www.newpaltz.edu/media/the-benjamin-center/P.Brief_2020Vision-Flipped%20classroom.pdf

9. Estes, M. D., Ingram, R., Liu, J. C. (2014). A review of flipped classroom research, practice,and technologies. International HETL Review, 4 (7), Retrieved from:https://www.hetl.org/feature-articles/a-review-of-flipped-classroomresearch-practice-and-technologies
10. Gojak, L. (2012, October). To Flip or Not to Flip: That is Not the Question! National Council of Teachers of Mathematics. Retrieved from http://www.nctm.org/about/content.aspx?id=34585
11. Hamdan, N., McKnight, P., McKnight, K., & Arfstrom, K. M. (2013). A Review of Flipped Learning. http://www.flippedlearning.org/review
12. Hertz, M. (2012). The Flipped Classroom: Pro and Con.Edutopia. Retrieved from:
    http://www.edutopia.org/blog/flipped-classroom-pro-and-con-mary-bethhertz.htm
13. Kandroudi, M., & Bratitsis, T. (2013). The Flipped Teaching as a collaborative learningapproach: Literature review. In: Proceedings of 3rd National Conference “Integration of ICT in the educational process” of the Hellenic Union ICT ineducation (EICT), Department Of Digital Systems, Univercity of Piraeus, Piraeus,10-12 May 2013, (in Greek).
14. Kim, M. K., Kim, S. M., Khera, O., &Getman, J. (2014). The experience ofthree flipped classrooms in an urbanuniversity: an exploration of designThe Internet and HigherEducation, 22, 37-50
15. T. T (2021). The implementation of flip classroom approach in academic course, VNU Journal of foreign studies, 27 (3), 149-170.
16. Noora H. et al. (2013). A review of flipped learning. DOI:4236/ce., Retrieved fromt: https://www.researchgate.net/publication/338804273_Review_of_Flipped_Learning

17. Rezaei Fard, Z., Shahrokhi, M. &Talebinezhad, M. (2022). Flipped Classroom Approach in ESP Courses: Focus on ESPStudents’ Critical Thinking and Engagement. Foreign Language Research Journal, 12 (1), 74-93
18. Strayer, J. (2007). The effects of the classroom flip on the learning environment: acomparison of learning activity in a traditional classroom and flip classroom thatused an intelligent tutoring system. Ph.D. dissertation, Ohio State University.
19. Zhang J. (2017). “Research on college English teaching model basedon flipped classroom,” Boletin Tecnico/Technical Bulletin,55 (15), 517–522
20. Zhou S. and Zhang T. (2017). “Research on the construction offlipped classroom model for English teaching based on spoc,”Revista de la Facultad de Ingenieria, 32 (14),267–273.