Table 3.

Group descriptives and associated t test values for repeated measures planned comparisons (see Multimedia Appendix 1).

Group		N	Mean	Standard deviation	Degrees of freedom	t	P	Cohen
Form A		129	0.92	0.91
Form B		129	0.90	1.04
Difference			0.01	0.59	128	0.25	.80	0.02
Mobile Phone Group
	Paper	63	0.85	0.93
	Mobile phone	63	0.89	1.04
	Difference		−0.03	0.66	62	0.42	.68	0.04
Tablet Group
	Paper	66	0.97	0.81
	Tablet	66	0.93	1.11
	Difference		0.04	0.53	65	0.68	.50	0.04

^aCohen d was calculated using original group standard deviations, rather than difference standard deviation [16].