## 3 Methodology  
The research was carried out in Poland in December 2021. The participants included 621 students from Polish universities. In our study, we used an online questionnaire (Google questionnaire). Google Forms offers the possibility of creating a form with questions, automatically collecting data and saving them to an MS Excel file. We gathered the surveys by posting the survey using Facebook pages. Links to the previously prepared survey were posted on the pages of all Polish technical universities. The research process is presented in Figure 1. The SERVPERF methodology, which is used to measure the level of service quality, was utilized in the development of the survey. The SERVPERF methodology [61; 62] is a type of SERVQUAL methodology [63; 64], which involves measuring service quality by asking customers to rate their perceptions of a service on a set of attributes. These attributes can vary between different industries. Based on a literature review [65; 66; 67; 68; 69; 70] (B1A stage), we prepared a list of 20 questions related to typical aspects of service quality, covering dimensions such as reliability, responsiveness, empathy, assurance, and tangibles (stage B1B). The original set of 20 questions was evaluated using the expert method (stage B2A). To assess whether a given question should be included in the survey to measure service quality, we used the expert method to measure the quality of service quality. Figure 1: Stages of the applied research procedure. quality, a survey was conducted among professionals who are engaged in e-learning and apply e-learning in their professional practice. The representatives of these two expert groups will differ in their competencies in various aspects. Therefore, it is necessary to establish a rule for assessing and selecting experts for the survey based on their competencies. It is crucial, then, to determine the level of their competencies using an appropriate indicator, and to set a threshold value above which an expert can be qualified to participate in the survey. Assessments of the competencies of experts and their qualifications will be conducted based on a self-assessment questionnaire. As a result of the self-assessment, a competence coefficient (Kk) will be determined, representing the arithmetic mean of the coefficients Kz--i.e., the familiarity coefficient--and Ka--i.e., the argumentation coefficient [81]. The formula (1) shows the competence coefficient:  
\[\text{Kk}=\frac{\text{Kz}+\text{Ka}}{2} \tag{1}\]  
The familiarity coefficient (Kz) aims to indicate the alignment between the expert's knowledge of the essence of the research problem and their actual expertise--where a narrow specialty of the expert signifies the highest rating. It is calculated for each expert by multiplying the chosen score from the questionnaire by 0.1. In this case, experts who have a satisfactory understanding of the problem are accepted--regardless of whether they are involved in its practical resolution--if they achieve a score for Kz \(\geq\) 0.5 [81]. A questionnaire was used to assess the experts' qualifications for the survey. The questionnaire evaluated the experts' familiarity with the given topic on a scale of 0-10, where the numbers signify the following:  
* 0--The expert is unfamiliar with the problem;
* 1-3--The expert has a weak understanding of the problem, but it falls within their area of interest;
* 4-6--The expert has a satisfactory understanding of the problem but does not participate in its practical resolution;
* 7-9--The expert has a good understanding of the problem and participates in its practical resolution;
* 10--The problem is within the expert's narrow specialization. The argumentation coefficient (Ka) aims to determine the value of the arguments used by the expert, where judgments based on the experts' own experience are valued the highest, while generalizations of knowledge and intuitive opinions are valued the lowest (see Table 1). It is calculated for each expert by summing the selected scores in various categories of argumentation.