The purpose of this study was to investigate the perceived service quality of QC Car Audio users and compare the quality of service provided by QC Car Audio stores classified by their demographic characteristics. The sample was 267 customers using the QC Car Audio service from January 2015 to January 2017. The statistics used for the data analysis included frequency percentage mean standard deviation and t-test was applied as well as the analysis of one-way ANOVA. The study found that the overall quality of QC Car Audio service provided by the customers was at the highest level. It was also found that the customers’ different gender age marital status education monthly income occupation and service location did not significantly vary in terms of the service quality perception towards QC Car Audio in the overall. When looking into each five aspects there were no significant differences. However different service locations yielded different service quality perception towards QC Car Audio at the .05 statistically significant.

This independent study was aimed to 1) explore the users’ demographic characteristics 2) level of perception of service quality and 3) comparison of demographic characteristics differences of the perceived service quality at Hua Chiew Thai – Chinese traditional Thai medication. The samples used in the research were 400 service users of Hua Chiew Thai – Chinese traditional Thai medication. The questionnaire was applied for the data collection. The statistics used for data analysis were descriptive statistics including frequency percentage mean standard deviation t-test F-test and the analysis of One-Way ANOVA. When the statistical significance. 0.05 was found multiple comparison test using Scheffes method was applied. The study results revealed that the users who differed in terms of demographic characteristics education level and marital status perceived the overall service quality differently.

The study on perception towards service quality of Siam Kraft industry Company Limited was aimed to investigate and compare service quality perception of Siam Kraft Industry Company Limited. The survey was accomplished among 207 Siam Kraft industry Company Limited customers as the sample group. The questionnaire with the reliability value of 0.97 was administered as the instrument for collecting data which were analyzed by the frequency distribution percentage distribution standard deviation t-test One – Way ANOVA and Scheffe. In case of 0.05 statistical differences was found Least Significant Different method was applied to verify each pair. The results revealed: 1. According to the respondent’s’ general information 140 were females (68.60 %) 92 people aged ranging from 30 to 40 years old (44.45 %). 124 or 59.90 held bachelor’s degrees and 69 people or 33.33 % had 5 to ten years work experience. 2. The perception towards service quality of Siam Kraft industry Company Limited in the overall was relatively high. When looking into each aspect the first item was credit service followed by finance delivery processed products and marketing services respectively. 3. As for the respondents ‘general statuses different ages and work experiences did not perceive service quality of Siam Kraft industry Company Limited differently at 0.05. However males and females perceived different marketing service; and different educational levels perceived processed products differently at 0.05.