4.2. Sample Size Determination
4.2.1. Non-Parametric Testing
We used the Chi-squared test to determine the representativeness of the recovered samples. First, we used non-parametric tests to measure the ratio of male to female students.
H0 = The gender ratio of students taught by flipped teaching is the same as that for traditional teaching.
The Chi-squared statistic was 0.011a, and the P-value = 0.917, which is greater than 0.05, so the null hypothesis (H0) was accepted.
4.2.2. Test of Homogeneity
We used the test of homogeneity to measure the distribution of two samples for the same variable. In analyzing samples from a private university in the central region of the country and a private university in the south, we hoped to determine whether the two counties and cities had similar distribution patterns and the same characteristics, to avoid external interference.
H0 = The sample size of flipped teaching is the same as that of traditional teaching.
The Chi-squared statistic was 213.000a, and the P-value = 0.468, which is greater than 0.05, so the null hypothesis (H0) was accepted.
H0 = The related department of flipped teaching is the same as that of traditional teaching.
The Chi-squared statistic was 2.562a, and the P-value = 0.109, which is greater than 0.05, so the null hypothesis (H0) was accepted.
Based on the above observations, the gender ratio of the sample population is consistent. It is also consistent with the homogeneity in related departments. Therefore, we used the sample size of the two classes as a follow-up measure. In addition, the sample size corresponds to 5 times the smallest variable.
4.3. Variables’ Mean and Standard Deviation
In terms of the average value of “mental load” for flipped teaching and traditional teaching, it can be seen that for X1 “I can understand the learning content of the course”, the average values are 4.56 and 4.37, respectively. This means that, under their current mental load, the students can understand the classroom teaching content. Variable with the lowest average value is: X6 “I have studied hard, but I still can’t keep up;” the average values are 2.20 and 2.03, respectively. This indicates that the students are keeping up with the course. The average value for “physical load” can be seen in the flipped teaching: X8 “My eyes are very tired”. This variable item is the highest, with an average value of 3.24. The average value for traditional teaching is 2.53, indicating that the degree of eye fatigue is close to the acceptable level. For X13, “I have experienced shortness of breath”, the average values for the two teaching methods were low, at 2.04 and 1.87, respectively, which both equate to “disagree” answers.
As for the average values of “time load”, different results were seen for the flipped teaching method. The average value for X14, “I think the context of the teacher’s explanation is clear”, was 4.55. The highest average value for traditional teaching was for X15 “I think the teaching schedule is appropriate”, at 4.14. The teaching methods of the two classes were different considering the average value of X16 “I can hand in the homework on time in class”, which indicated a large gap with values of 4.46 and 3.54, respectively. Classroom learning materials are previewed before class, which means that students can be more punctual about handing in “homework” during class. In traditional teaching, students who do not use video teaching and Supplementary Materials to preview the work at home in advance are required to hand in “homework” in class on time, and their performance is not as good as with flipped teaching. Finally, the average values of flipped teaching and traditional teaching for the “classroom interaction” section indicated that the teacher will assist students as much as possible with learning. The average values for the two were 4.67 and 4.05, respectively, for question X21, “I think the teacher will assist me as much as possible”. The lowest average was for X19, “When participating in class group assignments, I discussed and interacted well with my classmates”. The averages were 4.47 and 3.67, respectively, as shown in
Table 6.
4.4. Factor Analysis: Reliability and Validity
A reliability analysis measures the consistency and stability of the results. In this research, the Cronbach’s α value, suggested by Cronbach [
48], was adopted. If the Cronbach’s α value is less than 0.5, it is unacceptable. Kaiser [
49] proposed that the retention items of factor loadings should be at least 0.4. In the research of the Varimax rotation matrix, we can see that the factor loadings of variables X5, X6, and X16 are 0.341, 0.312, and 0.369. Therefore, we removed these three variables and then performed the reliability analysis. After deleting items with factor loadings <0.4, the reliability values were all greater than 0.5, which meets the acceptable criteria level (
Table 7).
Fornell and Larcker [
50] proposed that the square root of the average variance extracted (AVE) of each factor must be greater than the correlation coefficient between the two factors in order to have good validity. It can be seen from
Table 8 that the square root of AVE of mental load, physical load, time load, and classroom interaction was 0.710, 0.847, 0.808, and 0.829, respectively. All of these are acceptable levels.
4.5. Hypothesis Test
The experiment involved anonymous data on graphic design students from two classes. One of them was an experimental group and the other was considered a control group to compare the differences in flipped teaching. We aimed to determine whether there are significant differences between the flipped teaching and traditional teaching methods in terms of the cognitive load of students. A t-test (independent samples) was used to measure the two groups of classes. The results showed that the P-values of the four factors in the cognitive load <0.05 for flipped teaching and traditional teaching all had significant differences (as shown in Tables 9, 11, 13, and 15). The following is the series of hypothesis testing.
There is no significant difference in mental load between flipped teaching and traditional teaching (H1;
Table 9).
Based on the above result, a post hoc analysis method was used to find the detailed analysis of the mental load (
Table 10).
A number of studies have suggested that flipped teaching can help students to: (a) think effectively and critically; (b) solve problems; (c) understand more easily; and (d) memorize knowledge content, thereby achieving a good learning performance [
51]. Among the variables comprising “mental load”, only X1, “I can understand the learning content of the course”, did not reach significance (
P = 0.055); the other variables reached significant difference, indicating that, with both flipped teaching and traditional teaching, students can understand the learning content of the course. X2, “I can remember the professional skills of unit learning after being taught by the teacher”, had an average value of 4.45 for flipped teaching and an average of 4.0 for traditional teaching, which means that students are learning actively and independently. Experiments have proven that flipped teaching can promote the active and autonomous learning of students and enhance their achievements (
Table 10).
There is no significant difference in physical load between flipped teaching and traditional teaching (H2;
Table 11).
Based on the above result, a post hoc analysis method was used to find the detailed analysis of the physical load (
Table 12).
Meaningful teaching and learning require a lot of cognitive processing. In information processing and teaching design, unnecessary cognitive loads should be avoided. The only variables of “physical load” whose
P-values have no significant difference are X12 and X13, “I have a severe headache” and “I have experienced shortness of breath”. The average values of X12 are 2.34 and 2.06. The average values of X13 are 2.04 and 1.87, indicating that the students do not have these physical symptoms. However, students had significant
P-values for “My whole body is very tired”, “My eyes are very tired”, and “I have sore shoulders and neck/back and waist/hands and wrist”. These two different teaching methods led to significant differences in these variables (
Table 12).
There is no significant difference in time load between flipped teaching and traditional teaching (H3;
Table 13).
Based on the above result, a post hoc analysis method was used to find the detailed analysis of the time load (
Table 14).
In the past, a lot of research has proposed the benefits of online learning. The main purpose is to solve the problem of student absence so that students who do not attend class can review the key points at home. However, it was unexpectedly discovered that the same was true for students who were not absent [
10]. In flipped teaching, the teacher records short instructional videos before class, which allows students to preview the lecture content before the class, and then solve related problems in the classroom. The results show that the
P-values all have significant differences. The students who were taught in this way agreed with the statements “I think the context of the teacher’s explanation is clear”, “I think the teaching schedule is appropriate”, and “I think the degree of difficulty of the homework is appropriate”. These values were higher than for traditional teaching. The new teaching methods improve the motivation of students to learn independently and make better use of resources and time (
Table 14).
There is no significant difference in classroom interaction between flipped teaching and traditional teaching (H4;
Table 15).
Based on the above result, a post hoc analysis method was used to find the detailed analysis of the classroom interaction (
Table 16).
In recent years, scientific and technological information has become essential to people’s daily lives. Educators have also begun to perceive that traditional teaching methods and content (a teacher giving classroom lectures) cannot ensure that learners fully concentrate during classroom time, which may affect their learning interest and achievement. At present, many colleges and universities are using online learning platforms. The teacher uploads digital videos and teaching materials to provide learners with pre-class learning. Flipped teaching not only involves pre-class teaching videos but also allows learners to participate in classroom interactions during lectures. In the classroom, learners can discuss and solve problems with their classmates.
Some scholars [
5,
21,
25,
51,
52,
53] have proposed that flipped teaching is different from traditional teaching in that the traditional lectures are emphasized by “lecture teaching” first, with practice and problem solving as the teaching strategies after class. Flipped teaching focuses on collective interaction and solving problems in the classroom. It involves video lectures, quizzes, and exercises that are used as the course model before class. Results of the experiments show that the
P-values of variables X18 to X21 indicated significant differences (0.000 ***). This means that the learners have implemented classroom interaction and pre-class videos and materials. The average value of flipped teaching is higher than that of traditional teaching (
Table 16). Based on the above quantitative data analysis and results,
Table 17 indicates that we should reject the hypotheses.
4.6. Transcripts of Focus Group Interviews
This research used focus group interviews to assess the flipped teaching, and axial coding was performed. We aimed to understand the learners’ feelings and experiences in relation to the use of innovative mixed materials. We compile the interview transcripts below (at the GDC classroom of by Yi-Chieh Chen teacher):
Flipped teaching method (AC01)
Question: How do you think the learning method of flipped teaching is different from your past experience (AC01)?
Student (A-05): In the past, after the teacher entered the classroom, the teacher opened the textbook or handout, explained the contents according to the book, and then ended the class. But in the flipped teaching method, the teacher gave us mobile phones to use in class. Then after opening the mobile phone to download the app, the teacher allowed us to play some games and engage in creative thinking. I think it is very fun.
Student (D-03): The teacher is really cool. We all know that Yi-Chieh teacher often takes students to participate in design competitions and win prizes. Previous students obtained a prize of 100,000 NT dollars in the TISDC International Student Design Competition. This was the Brno Biennale Association Special Award and was on the news—so amazing. The teacher is very flexible and lively in class, and also encourages students to assist and discuss with each other, to arouse interest and motivation in learning. I really want to win the prize, and I am envious.
Student (F-02): I think TOLP is really easy to use. I’m not familiar with my classmates. Sometimes I can use the function of contacting my teacher and classmates on TOLP. You can also ask questions in the discussion board. If the teacher sees it, she will reply to me. I find it very convenient and practical.
Online learning with TOLP (AC02)
Question: What do you think of the online learning (TOLP) for pre-class tutoring and after-class remedial of ideas (AC02)?
Student (B-07): Hmm… I think I often can’t keep up with the class, but the teacher will put a lot of teaching materials and videos in TOLP for us to use to learn at home. Sometimes I am accidentally late, but I will check it again when I get home. If there are still problems, I will ask my classmates, and I should be able to keep up with the coursework.
Student (J-06): I think that although it takes some time to watch the videos and read through the other teaching materials at home, I can coordinate my time. At first, I found it a little troublesome, but after I became familiar with the software applications, I found them very convenient. Sometimes you are late for class or miss a class, but you can look at the information in TOLP at home to catch up on the relevant content.
Student (K-01): Every time, I read what the teacher is going to teach that day before the class starts. The previous teachers only provided a course outline. The teacher will record a GDC video in advance and put it in TOLP. This is very convenient: you know in advance what the teacher wants to teach, and you can learn it quickly.
Learning by classroom interaction (AC03)
Question: Do you think the current method of classroom interaction is different for your relationships with classmates (AC03)?
Student (G-04): I really like using Kahoot and Quizlet Live. The teacher uses these two apps to arrange games in groups for us. During the game, classmates will also help you. Sometimes the examination will use app software to give us tests, which is very exciting and I like it very much.
Student (C-05): The teacher uses the XMind app to draw a mind map for let us during class. This app is very easy to use, and the mind map can be made easily with connecting lines. During the class, we discussed with our classmates, played games, and thought about creativity. In this process, the teacher will check everyone’s progress and status. If you don’t understand, you can ask questions right away; it’s great.
Student (M-03): A lot of the homework the teacher will solve and discuss in class. For example, the teacher allows time for us to make sketches, and write down the keywords and images in our minds through the process of creative thinking and brainstorming. Then, you can think about your own artwork, or you can discuss it with your classmates. I think it’s better than trying to do it on my own at home.
Mental and physical load (AC04)
Question: Do you think that, now that the teacher is using flipped teaching methods, there will be an additional physical or mental load to cope with (AC04)?
Student (E-02): Originally, there was a lot of homework for students in the Visual Communication Department, but now the homework will be reserved for us to do in class a lot of the time. The teacher hopes that the problems can be solved and discussed in class, so I think it’s okay there is no trouble in this regard. But occasionally I feel that my shoulders are tight, it may be a frozen shoulder? I do not know…Then, when I am home, I will practice. Furiously practice my techniques, ah ah ah...
Student (I-06): I think the teacher will demonstrate the problem-solving method in class, but other teachers may not be doing this. I think this has solved a lot of problems; it’s great, there is no issue. And after I go home, I may be more interested; because I want to participate in the competition, I will spend time searching for information. Because I do regular exercises, I won’t be troubled by soreness.
Student (H-03): I think the students of the design department often draw pictures. Although sometimes I feel sore when I keep painting, I can accept it once I get used to it... Anyway, so long as the homework is complete and handed in on time, I will not flunk. Just fine, ha ha ha. I should add that I am painting at home and at school. Painting is an interest, and what I care about is painting.
Based on the content of the above focus group interviews, we can see that some students may be late or absent, but after using online videos and teaching materials, they can catch up to get good learning results. The benefit of flipped teaching is that one can control one’s own learning time. The learner can review the material before and after class according to his or her own time arrangements. With the development of the course content from simple to complex, it is essential to appreciate the importance of integrated course design. The TISDC international student design competition also enhances students’ interest and motivation.
To summarize the above interviews, due to the advent of smart phones, students are happy to use their mobile phones to gain knowledge during class. A mobile device is used as a test tool for using an app and to strengthen students’ interest in learning. TOLP online learning is regarded as a bridge between teacher and students. At the same time, app software such as Kahoot, Quizlet Live, and XMind leads to discussion and interaction between classmates and the peer relationship is strengthened. It also helps students to solve homework problems they cannot solve alone at home.
As for the mental and physical loads, the teacher has set aside a lot of classroom time for solving problems. Even if students have some physical troubles caused by a long drawing time, these can generally be solved through appropriate exercise and rest. Learning is not only to gain knowledge but also to help them know how to practice and make up for any lost learning adaptability.