Table 2.

Persuasive design principles and number of apps (N=28) that used the principle.

Design principles		Apps, n	Ƙappa (percentage of agreement)
Task support
	General informationa	16	.786 (89.3)
	Self-monitoring	12	.926 (96.4)
	Reduction	9	.836 (92.9)
	Logginga	9	.92 (96.4)
	Instructiona	7	.909 (96.4)
	Goal setting	3	1.0 (100)
	Micro tailoringa	3	.781 (96.4)
	Macro tailoringa	1	1.0 (100)
	Simulation	1	1.0 (100)
	Contextual cuesa	1	1.0 (100)
	Tunneling	0	1.0 (100)
	Trackinga	0	1.0 (100)
	Rehearsal	0	1.0 (100)
	Behavioral contracta	0	1.0 (100)
Dialogue support
	Reminders	10	1.0 (100)
	Suggestion	2	1.0 (100)
	Rewards	1	1.0 (100)
	Praise	0	1.0 (100)
	Similarity	0	1.0 (100)
	Personalization	0	1.0 (100)
	Social role	0	1.0 (100)
	Prompt self-talka	0	1.0 (100)
System credibility
	Surface credibility	26	.65 (96.4)
	Expertise	25	.837 (71.4)
	Verifiability	8	1.0 (89.3)
	Real-world feel	7	.884 (85.7)
	Authority	7	.837 (96.4)
	Third-party endorsements	0	1.0 (100)
Social support
	Social interactiona	1	1.0 (100)
	Social learning	0	1.0 (100)
	Social identificationa	0	1.0 (100)
	Social comparison	0	1.0 (100)
	Normative influence	0	1.0 (100)
	Social facilitation	0	1.0 (100)
	Cooperation	0	1.0 (100)
	Competition	0	1.0 (100)
	Recognition	0	1.0 (100)

^aPrinciples added from behavior change techniques.