Table 3.
Number of apps incorporating a particular PSD principle.
| Implemented principles (%) | Example | |
|---|---|---|
| System credibility | ||
| Real-world feel | 98.3 | Providing contact data of developers |
| Authority | 14.2 | Citations of clinicians |
| Third-party endorsements | 28.3 | Recommendations of diabetes institutions |
| Verifiability | 22.5 | Providing source of information and links to it |
| Dialogue support | ||
| Praise | 23.3 | Feedback/compliments on tracked data |
| Rewards | 2.5 | Collecting stars for engaging in lessons |
| Reminders | 16.7 | System based daily pop-up messages |
| Suggestion | 85.8 | Recipes for healthy nutrition |
| Similarity | 4.2 | Stories of other diabetes patients |
| Social role | 7.5 | Guidance by an avatar |
| Primary task support | ||
| Reduction | 16.7 | Dividing tracking in small simple steps |
| Tunneling | 6.7 | Implementing sequential lessons |
| Tailoring | 25.0 | Adapting information according to type of diabetes |
| Personalization | 10.0 | Possibility to customize interface |
| Self-monitoring | 28.3 | Feature for glucose tracking |
| Simulation | 0.8 | Calculator how glucose level changes during the day |
| Rehearsal | 5.0 | Knowledge quiz |
| Social support | ||
| Social learning | 2.5 | Board showing activity of other app users |
| Social comparison | 0 | Comparison of user’s response to others’ responses |
| Normative influence | 13.3 | Comparing glucose values to healthy peers |
| Social facilitation | 7.5 | Online discussion forum |
| Cooperation | 1.7 | Giving advice in small peer groups |
| Competition | 0 | Leader boards on daily activity level |
| Recognition | 7.5 | Liking and posting achievements |
System credibility, dialogue support, primary task support and social support are the four categories of persuasive system design. Each category consists of seven principles.