## 2 Materials and Methods
### Multimedia Teaching Material Design and Presentation Methodology  
New multimedia teaching content was specifically designed for this research. To achieve an experience that was as realistic as possible and to have closer contact with the instructor, previously recorded lectures and PowerPoint presentations were used to create multimedia material. The lectures used for this research were recorded using professional equipment. The content and context of the multimedia education material used for the experiment were related to the mobile computing course, because its syllabus has various objectives and different levels of complexity. Therefore, this course covers topics and objectives commonly interesting to all students who participate in testing. The created multimedia material, by using transition effects in the form of video segments merging, enables students to receive pictorial, audio, and text information from the multimedia presentation, including the instructor's voice within multimedia. In this manner, students have the impression that the instructor is present in the classroom, to maintain their focus and attention during the learning sessions. By combining audio and visual information in multimedia teaching materials, students can process them simultaneously and efficiently, which aligns with the cognitive theory of multimedia learning [34]. There are several ways to reduce cognitive load in multimedia learning, and one of the methods is to use the segmentation principle. This means that the use of pauses between successive segments enables the achievement of better knowledge transfer. Two different methodologies of presentation of the teaching materials were used to analyze their effectiveness. In general, the multimedia material can consist of educational multimedia sequences, pauses, additional non-education content, and segments containing questions about the subject matter. The subject of the investigation was the influence of inserting additional content or pauses in the multimedia teaching materials on the students' knowledge level and QoE. For this research, two types of multimedia material were created using several educational sequences with different content, context, and complexity. Questions for the assessment of the level of acquired knowledge were also used in the design of testing multimedia material. Two methodologies for the design and presentation of the linear multimedia content are shown in Figure 5.  
The first methodology was based on the principle of segmentation of multimedia content (Figure 5a). The segmented linear multimedia (S-LM) was created using educational sequences, test questions, and pauses inserted between them. In this testing methodology, after displaying each multimedia sequence, questions related to that sequence were inserted. Figure 5: The educational multimedia design and presentation methodology: (**a**) segmented linear multimedia (S-LM), (**b**) non-segmented linear multimedia (NS-LM). Before and after each question, students had a 10 s break. Therefore, the educational sequences and the questions related to them are repeated evenly (Figure 5a). In the second methodology, the non-segmented linear multimedia (NS-LM) material was presented to students (Figure 5b). In the creation of NS-LM, the smooth transition between the educational sequences was used. This methodology implies that all educational sequences are displayed one after another without pause intervals, followed by a full set of testing questions on the level of knowledge acquired by watching the sequences (Figure 5b). Before starting to answer the questions, students have a 90 s break. Each educational multimedia sequence (educational sequences 1-5) lasts approximately 5 min. For the S-LM methodology described in Figure 5a, the time allotted for answering each group of questions is 3 min. In the case of NS-LM methodology described in Figure 5b, students have 15 min to answer all questions.