## 4 Results and Discussion
### Effects of Socio-Demographic Variables on Overall Opinion of Customers  
To analyze how socio-demographic factors influence customers' general opinions regarding the service provided by the lab, the responses from the third section of the questionnaire were examined separately based on gender, age, academic qualifications, and employment status. Figure 11 illustrates the percentage breakdown of responses to the third section of the questionnaire, segmented by the socio-demographic variables mentioned above. With respect to the influence of gender on customers' opinions, it is observed that the percentage breakdown of responses differed by less than 0.5%. When comparing response frequencies by age group, positive opinions differ by 4.0% (17.6% vs. 13.6%), 2.6% (65.7% vs. 63.5%), and 1.4% (10.2% vs. 8.8%) for very satisfied, satisfied, and slightly satisfied, respectively. Negative opinions show differences of 1.1% (4.8% vs. 3.7%), 2.7% (4.6% vs. 1.9%), and 3.7% (4.6% vs. 0.9%) for slightly dissatisfied, dissatisfied, and very dissatisfied, respectively. Additionally, there is a trend of more positive opinions from customers over 45 years old and more negative opinions from those under 45 years old. When comparing response frequencies by academic qualifications, positive opinions differ by 6.1% (17.7% vs. 11.6%), 5.8% (67.3% vs. 61.5%), and 2.1% (9.8% vs. 7.7%) for very satisfied, satisfied, and slightly satisfied, respectively. Negative opinions show differences of 5.1% (7.7% vs. 2.6%), 6.4% (7.7% vs. 1.3%), and 2.5% (3.8% vs. 1.3%) for slightly dissatisfied, dissatisfied, and very dissatisfied, respectively. Additionally, there is a trend of more positive opinions from customers with lower academic qualifications and more negative opinions from those with higher academic qualifications. Finally, regarding the impact of employment status on customers' opinions, it is observed that the percentage breakdown of responses varied by less than 1.6% across all categories, apart from students. Given that this group represents only 2.7% of the total sample, it is not feasible to include them in this comparative analysis. However, it is noteworthy that all student respondents expressed positive opinions. The data analysis reveals differences in customers' opinions about the service provided by the lab based on socio-demographic factors such as age and academic qualifications. These variations can be attributed to differences in expectations, evaluation standards, and individual experiences. The data indicate that certain age groups and levels of academic qualification have more critical opinions, reflecting the influence of factors such as life experience, educational demands, and professional expectations. For example, older customers and those with lower educational levels tend to express more positive opinions, possibly due to greater tolerance for minor service shortcomings and adjusted expectations. In contrast, younger customers and those with higher educational levels may have higher expectations and stricter standards, resulting in more critical evaluations. These findings align with [PERSON] et al. (2018), who indicate that satisfaction depends on customers' perceptions and expectations.