Table 2.

Mean readability statistics. Free versus paid: comparison of mean reading grade level (RGL), mean word count, and mean reading ease between free and paid apps from both the Android and Apple markets. The P values for the t tests between the two app types show that there is no significant difference between mean RGL, word count, and reading ease.

Statistic	All appsa	Free apps	Paid apps	P value
N	64	30	34	--
Mean RGLb	12.78	13.09	12.51	.15
Mean word count	2425	2355	2487	.79
Mean Flesch reading ease	42.73	42.3	43.1	.65

^aColumn summarizes results for all apps included in the analysis; it was not included in the significance test for the P value in the last column.

^bRGL: reading grade level.