Table 2.

Validation of list equivalency for split-halves approach on the SIT.

List 1 sentences	Number of words in List 1	List 2 sentences	Number of words in List 2	r of intelligibility	Mean of intelligibility differences
a 5, 6, 9, 10, 11, 14	55	7, 8, 12, 13, 15	55	.92	0.35
5, 7, 9, 10, 12, 15	58	6, 8, 11, 13, 14	52	.95	−0.04
5, 7, 10, 11, 13, 15	60	6, 8, 10, 12, 14	50	.94	−0.2
5, 8, 9, 12, 15	49	6, 7, 10, 11, 13, 14	61	.92	−0.28
5, 8, 9, 10, 13, 14	59	6, 7, 11, 12, 15	51	.94	0.11
5, 6, 9, 11, 13, 15	59	7, 8, 10, 12, 14	51	.93	−0.38
b 5, 7, 9, 11, 13	45	6, 8, 10, 12, 14	50	.93	0.2

Note. For each iteration of the split-halves, the 11 sentences of the Sentence Intelligibility Test were randomly divided into two lists. In each iteration, we calculated the total number of words in each list, the correlation (r) between the two halves, and the mean of the differences between the halves. Because no iteration substantially improved the correlation between the two halves, and the mean of the differences was relatively normally distributed (as visually examined on histograms) for each iteration.

^a The division that was chosen because it equally distributed the number of words in each half.

^b Sentence 15 (longest sentence length) was removed in this iteration to examine whether this would change the correlation between halves.