## 3 Materials and Research Methods
### QoE Questionnaire and Selection of Research Variables  
In research considering the assessment and measurement of \(QoE\), two basic approaches are most often applied:  
* Service level measurements represent subjective measurements. They are most often carried out by agents accessing telecommunication services and responding to the created research questions at the end.
* Network level measurements (objective approach) allow the estimation of \(QoE\) values depending on the measured values of network QoS parameters (e.g., bit error ratio (BER), packet loss ratio (PLR), delay, etc.) [24; 32].  
Subjective assessment is considered the most accurate approach to measuring \(QoE\), where a discrete MOS scale of five levels is used to quantify factors affecting \(QoE\): 1: bad, 2: poor; 3: fair, 4: good, 5: excellent [25; 33]. In this research, the evaluation of user \(QoE_{i}\) is carried out with a subjective approach and a survey method, based on which a research instrument was created--a \(QoE\) questionnaire with 11 questions [15], through which five reconstructed groups of paired factors affecting \(QoE_{i}\) were presented.  
In order to model \(QoE_{i}\), a selection of research variables was made on the basis of the questions in the questionnaire. Ten independent/input variables (\(X_{1}\)...\(X_{10}\)) were identified, which were defined by questions 1-9 of the questionnaire: age (\(X_{1}\)); gender (\(X_{2}\)); legal-regulatory affiliation of the organization/firm (\(X_{3}\)); provider(s) with whom the user has experience (\(X_{4}\)); qualitative level of experience--perceived level of QoS (\(X_{5}\)); level of satisfaction with the price of the provider's services (\(X_{6}\)); evaluation of the user's legal security in interactions with the service provider in the area of service provision on the basis of contracts and payment of bills by cost calculation (\(X_{7}\)); user experience expressed by characteristics for four traffic classes (X\({}_{8}\)); user experience expressed by levels for four traffic classes (X\({}_{9}\)); length of user experience of the provider's services (X\({}_{10}\)).  
Figure 1 graphically shows how the five observed groups of paired factors affecting \(QoE_{i}\) are represented by \(11\) questions in the questionnaire, based on which, in the next step, three classes of research variables are defined. It is noticeable that the input independent variables (X\({}_{1}\)...X\({}_{10}\)), transition variables (D\({}_{1}\)...D\({}_{10}\); C\({}_{1}\)...C\({}_{5}\)) and an output dependent variable \(QoE_{i}\) were identified.  
In addition to the identified independent variables, in Figure 1 it can be seen that question 10 in the questionnaire defines 10 transition variables as indicators of satisfaction (_Delight-D_) up to the level of delight, and, in question 11, five transition variables as indicators of dissatisfaction (_Complaint-C_) up to the level of anxiety for the specific user service. Satisfaction indicators represent the effects of online services on the user: curiosity (D\({}_{1}\)), creativity (D\({}_{2}\)), communication (D\({}_{3}\)), personality (D\({}_{4}\)), courage (D\({}_{5}\)), confidence (D\({}_{6}\)), charisma (D\({}_{7}\)), competence (D\({}_{8}\)), common sense (D\({}_{9}\)), and memory (D\({}_{10}\)). Dissatisfaction indicators are defined by connection of online services with the following forms and measures of rigidity that services cause in users: interpersonal (C\({}_{1}\)), behavioral (C\({}_{2}\)), structural--longing for structure and coping with the lack of structure (C\({}_{3}\)), prospective anxiety (C\({}_{4}\)), inhibitory rigidity (C\({}_{5}\)). The two groups of indicators represent subjective user factors, which, based on a mathematical model, enable a direct assessment of the quality of user experience \(QoE_{i}\) as a dependent variable in the evaluation model.