We examine the methods for evaluating service quality in public art museums. Specifically, we will conduct a multi-group questionnaire survey of museum users on their satisfaction with the services provided by public museums. Using selective multigroup principal component regression analysis—which combines principal component analysis and multiple regression analysis—we will statistically examine the factors that public art museums should emphasize when providing services to their users. The four-page questionnaire will comprise three groups: hardware (building and interior), software (staff responses), and exhibition content. Each question will be rated on a 7-point Likert scale. We named the survey scale the indicators for art museums’ service quality scale. The scale comprises three question groups. The eventual survey will be conducted at the Higashihiroshima City Museum of Art for six business days on the third week of August 2022. Self-administered questionnaires will be distributed to visitors to the special exhibition. We are disclosing our research methods and data analysis procedures prior to conducting the research to prevent hypothesizing after the results are known, and to ensure the transparency of the research. In addition, presenting the details of the research implementation and data analysis methods can promote the accuracy of follow-up and replication experiments. Our proposed scale has the following advantages. First, it is simpler than the existing SERVQUAL-based survey framework, which is a 5-group scale, and is expected to reduce the burden on respondents and increase the response rate in actual surveys. Second, the fact that the opinions of those in charge of art museums were heard from the very beginning of the formulation of the research framework, makes the explanatory power of the analytical model, as expressed in the coefficient of determination of the multiple regression analysis, high for a scale targeting public art museums.