## 3 Materials and Methods
### Methods
#### 3.2.1 Questionnaire Design
To establish a hierarchy among key attributes, it is required to organically design the hierarchy between attributes related to decision-making, that is, criteria and alternatives. The purpose of this study is as follows: the first class was to select intelligent CPTED systems based on municipal control centers and the second class was to identify seven evaluation criteria for evaluating alternatives. The third class of evaluation alternatives includes the 12 service models selected above (Figure 1). Prior to the questionnaire survey, this study conducted a pilot survey and analysis with 13 PhD researchers who had a good understanding and knowledge of service elements and analytical models. From the pilot survey and analysis, this study double-checked the overall structure of the questionnaire survey, amended some terms in alternatives and evaluation criteria, and tested the analytical model. To ensure the multi-criteria decision-making (MCDM)-based expert questionnaire structure while making it easier for evaluators to understand the survey, this study gave the following guidance: the purpose of the survey, the concept of intelligent CPTED (including a concept map), as is/to be (the current CPTED vs. changes when incorporating intelligent CPTED), evaluation criteria, the scale and decision-making hierarchy of evaluation criteria, the description and example of the alternatives of technology elements, and a questionnaire example. For this survey, working-level employees in municipal control centers were selected as the evaluators to provide more professional and practical decision-making support in introducing intelligent \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Category** & \multicolumn{1}{c}{**Sub-Category**} & \multicolumn{1}{c}{**Description of the Evaluation Criteria**} \\ \hline \multirow{3}{*}{\begin{tabular}{c} Conformity with the purpose of \\ crime prevention \\ \end{tabular} } & Crime prevention effectiveness & Effectiveness on crime prevention from applying the service \\ \cline{2-3}  & Policy conformity & Conformity with government and municipal crime prevention policies \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} Service conformity \\ \end{tabular} } & Competitiveness with existing services & Competitiveness and usefulness with existing facilities/technologies/services \\ \cline{2-3}  & Growth in the service sector & Technology trends and market potential in the service sector \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Feasibility \\ \end{tabular} } & Economic viability & Effectiveness on investment, economic viability, and commercialization potential \\ \cline{2-3}  & Field applicability & Applicability to the field, including risk management (e.g., personal information and administrative delays) and collaboration with competent organizations (e.g., 112) \\ \cline{2-3}  & Sustainability & Efficient management operation and sustainability \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Evaluation criteria for intelligent CPTED technology elements. Figure 1: Hierarchy structure. CPTED systems. A total of 48 evaluators selected in this study were experts who operated crime prevention services. Hence, they had a very good understanding of this study and survey, which improved the reliability of the results of the analysis. This survey was conducted online in writing for two weeks from 7 th to 20 th April 2021. Under Article 33 of the Statistics Act in Korea, this study specified and informed the participants that all of their responses would be used for statistical purposes only, and the survey was conducted after obtaining their consent. The survey and related study were reviewed and approved by the Institutional Review Board of Gachon University (1044396-202303-HR-039-01). Accordingly, the need for consent was waived. More specifically, this survey ensured anonymity for all participants and fully informed them of the reason why the study was conducted, how the data would be used, and whether there was any risk.