*3.3. Questionnaire Design and Data Collection*

The choice set in the experiment questionnaires was based on level-specific combinations of attributes as seen in Table 1. A full factorial design of all 486 (35 × 2) choice profiles is not possible to consider. Thus, a fractional factorial orthogonal design is generally used [41,42]. In the present study, 18 profiles derived from an orthogonal design using SPSS (IBM, Armonk, New York, USA). 23 were used for the choice set. Survey respondents randomly selected 3 of these 18 profiles at each round, and either chose their favorite choice or chose none of them. The experiment was conducted in 6 rounds with all respondents. The number of valid responses was 563, with the total number of experimental responses at 3378.

The target population of the present study was night tourism visitors to Suwon Hwaseong Fortress who were over 19 years old. A pretest was conducted in order to increase the objectivity of the survey and to increase the validity of the questionnaire. After the revision of the questionnaire, the main survey was conducted. The survey was conducted on weekends and weekdays over 17 days in night tourism periods of Suwon Hwaseong Fortress, from 9–25 August, 2019, using face-to-face 1:1 surveys. Systematic random sampling was used at survey areas. In addition to CE items, the survey consisted of items about night tourism preferences, Suwon Hwaseong Fortress visiting behavior, and demographic characteristics. Each survey took about 15 minutes to complete.

### **4. Results**
