Table 3.
Questionnaire results of the usability substudy (n=9).
| Variables | Disagree, n (%) | Rather disagree, n (%) | Somewhat agree, n (%) | Fully agree, n (%) |
| Joy: I enjoyed the 7 days of testing. | N/Aa | N/A | 5 (56) | 4 (44) |
| Integration: The use of the GPSb device is easy to integrate into my everyday life. | N/A | 1 (11) | 3 (33) | 5 (56) |
| Time and activity: While using the GPS device, I need more time for my daily activities outside the home. | 4 (44) | 1 (11) | 3 (33) | 1 (11) |
| Battery level: The battery level lasts long enough for everyday use. | N/A | 1 (11) | 2 (22) | 6 (67) |
| Damage: I am afraid of damaging the GPS device. | 6 (67) | 2 (22) | 1 (11) | N/A |
| Privacy: I think that my personal data collected with the GPS device are properly protected. | N/A | 1 (11) | 2 (22) | 6 (67) |
| Takeaway: I always remember to take the GPS device with me when I leave the house. | N/A | 1 (11) | 2 (22) | 6 (67) |
| Comprehensibility: The external labeling of the GPS device is easy to understand. | N/A | N/A | 3 (33) | 6 (67) |
| Charging: The GPS device is easy to charge. | N/A | 1 (11) | N/A | 8 (89) |
| Help: When problems occur with the GPS device, I know whom to contact for problem solving. | N/A | 1 (11) | N/A | 8 (89) |
| Usefulness: The data collected by the GPS device are useful for (health) science. | N/A | N/A | 4 (44) | 5 (56) |
| Time: Filling out the questionnaires took too much time. | 5 (56) | 1 (11) | 2 (22) | 1 (11) |
aN/A: not applicable (ie, no participant responded in the category).
bGPS: global positioning system.