Table 2.

Summary of item response theory scale scores, overall and by variables of interest (see Multimedia Appendix 1).

Condition		N	Mean	Standard deviation
Overall		258	0.91	0.98
Modality
	Paper	129	0.91	0.87
	Mobile phone	63	0.89	1.04
	Tablet	66	0.93	1.11
Form
	A	129	0.92	0.91
	B	129	0.90	1.04
Modality × Form
	Paper × A	65	0.85	0.92
	Paper × B	64	0.98	0.82
	Mobile phone × A	32	0.93	1.02
	Mobile phone × B	31	0.85	1.08
	Tablet × A	32	1.05	0.79
	Table × B	34	0.81	1.34