The assessment of the reliability of physical activity questionnaires was obtained from four samples, collected at different times and locations. The author used a quota sampling technique to select samples. First, the author randomly selected one senior center, one residential culture center, one sports center, and one community park in Samcheok city, South Korea. Second, the author randomly selected 50 samples from each of the centers. The samples included in Samcheok residents aged over 65 who were participating in recreational programs provided by the community centers (senior center, residential culture center, and sport center). At the centers, four research staff members conducted face to face interview surveys between the survey period (6:30 am to 11:30 am and 2:00 pm to 9:00 pm). The retest was scheduled to be administered four weeks after the first face to face interview. The retest period was May 1 to May 30, 2019. Of the 200 questionnaires, 117 residents completed the survey. 44 (37.6%) were males while 73 (62.4%) were females. Participants ranged in age from 65 to 88 years old.
Physical activity pattern questionnaire
Because the main document of WHO’s physical activity recommendation emphasizes the combination of aerobic, resistance, and flexibility exercise, the questionnaire was developed to capture WHO’s physical activity recommendations and different types of physical activity. 17 items of 23 items were selected based on Cho’s study  and the public health organizations’ physical activity recommendations [5, 6]. Items were discarded from the following criteria such as items with learning effects, response rate close to 0%, and high semantic similarity. The questionnaire was divided into two parts, a demographic factor and physical activity pattern factor (aerobic activity, muscular strength activity, and flexibility activity).
An expert panel in the field of sports & leisure and recreation was invited to classify the activities into three different types of physical activities. The categorizations of physical activities were aerobic exercise & sports (walking, biking, jogging, swimming, aerobic, basketball, softball, soccer, golf, table tennis, badminton, football, etc.), flexibility exercises (stretching, yoga, Pilates, calisthenics, etc.), muscular exercises (weight training, free weight training, etc.). An expert panel in this study determined items to assess aerobic, muscular, and flexibility activity behaviors. To assess aerobic activity patterns, four items (frequency, intensity, duration, and overall length of physical activity during their leisure time) with usage of a five-point Likert-type scale were included. For example, “how often do you participate in the activity in your free time?” The frequency of physical activity was categorized as “almost every day (5)”, “4-5 days/week”, “3 days/week”, “1-2 days/week”, and “very infrequently (1).”
Regarding the assessment of muscular activity patterns, again four items (frequency, intensity, duration, and overall length of physical activity during their leisure time) with usage of a five-point Likert-type scale were included. For example, “how intensely do you participate in the activity?” The intensity of activity participation was categorized as “very hard (5)”, “hard”, “moderate”, “light”, and “very light (1).”
To assess flexibility activity patterns, four items (frequency, intensity, duration, and overall length of physical activity during their leisure time) with usage of a five-point Likert-type scale were included. For example, “how long do you do the activity in your free time?” The duration of physical activity participation was categorized as “less than 20 minutes (1)”, “30 - 50 minutes”, “60 - 80 minutes”, “90 - 110 minutes”, and “more than 120 minutes (5).”
Procedure and analysis
After obtaining an ethical clearance by the authentic ethical committee of Daegu University, copies of the survey questionnaires were distributed to each of the 200 participants in the community centers from the four different places in Samcheok, South Korea. The written consent forms and questionnaires were distributed to participants by the research staff. The participants were informed that participation in the study was voluntary and they were free to withdraw from the study at any time. At retesting, four trained survey interviewers conducted one-on-one interviews with 117 respondents. Of 200 respondents, 83 respondents did not participate in the study owing to a change in shift pattern or a summer holiday in the survey period. Therefore, the study sample comprised 117 residents whom agreed to participate in the study.
The test-retest repeatability was assessed using the Cohen’s kappa statistics. According to Fleiss and Cohen , an agreement of less than 0.40 was considered as poor, between 0.41 and 0.59 as fair, between 0.60 and 0.74 as good, and of 0.75 or more as excellent. Internal consistency was assessed by the Cronbach’s alpha coefficient. According to Nunally and Bernstein , an alpha over 0.7 indicated a high reliability, over 0.5 a moderate reliability, and below 0.2 a low reliability. Data processing used the SPSS software version 24.