TABLE 2.

Pre-test performance and performance change (mean ± SEM) in the size of the isolated-letter span for the control group and the two training groups.

		Pre-test (bits)	Post-pre difference	Retention-pre difference
Control	2.5°	59.64 ± 0.16	−0.57 ± 0.26	/
	1°	57.27 ± 0.65	−0.13 ± 0.57	/
With-repetition	2.5°	59.17 ± 0.25	0.60 ± 0.26	0.30 ± 0.20
	1°	57.14 ± 0.46	1.77 ± 0.53	1.27 ± 0.34
Without-repetition	2.5°	59.34 ± 0.32	0.70 ± 0.31	0.65 ± 0.41
	1°	57.67 ± 0.55	1.17 ± 0.62	1.64 ± 0.61

For the without-repetition group, retention/pre difference was calculated based on the five observers who returned for the retention-test.