Scoping Review of Flipped Learning in Engineering Education

Real opportunity to use digital technology such as flipped learning has been used in several fields, uncovering diverse benefits regarding its usage. Flipped learning make this possible through mixed environments that allow the combination of learning and discussion courses topics. This scoping review presented that there is potential in using flipped learning in education environment. The results from this systematic review provide valuable information regarding to enhance individual learning.

The reforms established in higher education has highlighted the importance of the educational model's effectiveness in equipping university studies with the critical thinking and skills that they need to develop their future professions (Jdaitawi, 2020). To be successful, engineering graduates need to fully comprehend principles and practices of engineering, to collaborate in teams, to communicate effectively and to work in risky and uncertain situations (Adamson & Daling-Hammond, 2012; Meier, Williams & Humphreys, 2000). Engineering education trends requires developing both the technical and non-technical skills of students (Male, 2010; Peter, Khoo, Cowie, Scott & Round, 2017). Educators need to develop curricula to allow the development of such skills among students. Throughout the past few decades, researchers have been exerting efforts towards determining the drivers of learning success among students at all levels and educators have been attempting to shift from an instructor-focused learning environment to a student-centered one (Bansal et al., 2020). Several learning methods have been adopted and developed in the present times to adapt to the dynamic changes in the society, science and technology (Sojayapan & Khlaisang, 2018). One of the top and extensively utilized learning methods from technological and pedagogical developments is flipped learning. In the learning and teaching realm, flipped learning is deemed to have significant contributions, while at the same time, it enhances the students' learning outcomes (Jdaitawi, 2020; Rathner & Schier, 2020; Akcayir & Akcayir, 2018). In the field of engineering, flipped classroom approach has been evidenced to enhance the performance of students (Jose et al., 2020), their learning experience (Turnbull, 2018) and their learning perceptions and ultimately achieve their satisfaction (Baytiyeh & Naja, 2017). It has also been proven to be useful in changing the students' study behavior and habits (Nielsen, 2020), and in supporting positive leisure attitudes and connectedness development (Jdaitawi, 2020). Flipped learning can be defined as the platform that deliver the passive teaching activities online (or through another medium), which the student accesses in his/her own time (homework), whereas active (student centered) learning activities are completed in the classroom ( Literature generally focused on the determinant effectiveness of flipped learning strategy in engineering education, with studies presenting an extensive review of flipped learning factors remaining few and far between. In this regard, this study conducts a systematic literature review to identify the flipped learning status in the field of engineering education and it examines categories of analysis for this purpose and flipped learning advantages, limitations, effectiveness in the same context. The analysis of the different categories would stress on the emerging trends, opportunities, challenges and literature extension and visions towards the objectives and outcomes of its future usage. Flipped learning in engineering education is examined on the basis of the following research questions.
1. What are the skills achieved through flipped learning use in the engineering education? 2. What are the most education levels used in flipped learning engineering studies? 3. What are the advantages and challenges related to flipped learning in engineering studies?

Methodology
The study adopted Arksey and O'Malley (2005) and Kitchenham's (2004) four-tiered systematic review of studies involving the following phases: 1. Identification of research questionsin the first phase, the trends in educational flipped learning studies conducted from 2015 to 2020 in were identified; flipped learning research dedicated to engineering education, 16 studies were selected from the databases and were deemed appropriate for the objectives of the study and the last phrase is required considering the research questions, which read, 1) What are the skills achieved through flipped learning use in the engineering education? (2) At which education level is flipped learning technology most frequently used for engineering students? and 3) What are the advantages and challenges related with flipped learning in engineering education?

Results and Discussion
To begin with discussion of results, one of the questions formulated for this study reads, "what are the skills achieved through flipped learning assist in engineering field?". The results from the engineering education studies were coded and tabulated in Table 1-the table enumerates Learning outcomes Enhanced students problem solving and critical thinking, selfconfidence and teamwork skills. The second research question queries at which education level flipped learning is most frequently used in science education and based on Table 2, many of the flipped learning studies were carried out on the level of bachelor's degree students 15 studies (93.75%) and this is followed by one study conducted among master and PhD students in engineering education (6.25%). The objective of flipped learning mode is to boost the students' motivation, explain topics to them and enhance their learning experiences and engagement in their learning activities. Many of the teaching-learning sessions were based on practical instruction and hence, computer-assisted instruction is an effective method that can be availed from by higher education in several academic year. Meanwhile, studies that focused on using flipped learning and its benefits among master and PhD students are still limited and this limitation may be attributed to the hours loads and maturity level as well as bachelor's degree students need more encouragement, and they are less self-direct learners compared with postgraduate students. Therefore, this study makes a call to examine the effectiveness of flipped learning model among master and PhD students in engineering education field.   (Wells & Holland, 2015). Length of the videos and time required for students to master the learning materials is another challenge as flipped learning required sufficient technical support to facilitate delivery contents. (Koo et al., 2016;Velegol et al., 2015). Another possible limitation maybe related to the availability of tool to measure flipped learning. Additionally, Finally, flipped learning is a favor technique in those practical knowledge-based courses, as there are many theoretical knowledgebased courses.

Conclusion
The extensive use of flipped learning only began in the last few decades in providing science information and curricula to engineering students. In this study, the focus is laid on the effectiveness of flipped learning in affecting the outcomes of students in engineering courses. The study carried out a systematic review to determine the use of flipped learning strategy from the perspective of students, highlighting the strengths and weaknesses of approaches, and providing data to comprehend the way flipped learning can minimize the different limitations and challenges that students of engineering courses face when it comes to using flipped learning. The literature review on the use of flipped learning technique showed a total of 16 implementations with the studies agreeing on the positive role of flipped learning technique in engineering courses in different levels (bachelor, master, and PhD level students). The studies also showed different technologies utilized including computer, laptop, and mobile devices. They revealed that flipped learning mode was successful in enhancing the student's skills and positive learning outcomes.

Limitations and suggestions
This study has some limitations like other studies, in which the majority of the studies did not examine the influence of students' characteristics, which needs to be examined in future studies. Majority of them also used small-sized samples of participants, and thus, future studies should consider bigger sized samples to validate the findings. Another limitation relates to data collection methods, which future studies should consider, so that they can adopt other approaches. This systematic review presented information concerning ideas and solutions as to how science achievement among students can be improved through flipped learning strategy implemented.