Table 4.
Frequency and severity of encountered problems during the completion processes of all participants.
| Problem | Number of participants | Frequency | Severity rating |
| 1. Accidently skipping a screen by double tapping on the next button | 8 | 16 | Serious |
| 2. Double-tap on answering option causing activation and deactivation of the answer of choice | 1 | 1 | Low |
| 3. Skipping a screen by accidently touching the next button with the palm of the hand | 1 | 1 | Low |
| 4. Not using the navigation function of the photo gallery in question 4 causing the participant not seeing all presented response items | 2 | 2 | Medium |
| 5. Touching the text underneath a photo in question 4 to select an activity instead of touching the photo itself causing the activity not to be selected | 3 | 30 | Serious |
| 6. Not able to see whether or not a selected answer is activated (not accentuated enough) | 8 | 8 | Medium |
| 7. Not knowing how to get to the next screen | 1 | 1 | Medium |
| 8. Pushing too hard or tapping too soft on the touch screen causing the touch screen not to respond | 11 | 40 | Serious |
| 9. Not able to correct a wrong answer | 8 | 13 | Serious |
| 10. Not reading the text above the photos of question 5 causing the participant to keep on performing the task given with question 4 | 4 | 8 | Medium |
| 11. Not noticing that the multiple numerical rating scale-effort scores in question 8 are related to different activities, which by mistake results in identical scores for different activities | 1 | 1 | Low |
| 12. Scoring the body chart in question 2 mirrored | 2 | 2 | Low |
| 13. Scoring (serial) questions that do not apply to the participants’ situation (forced by the software) | 1 | 4 | Medium |