TABLE 4.

The differences in age, non-verbal intelligence, and executive functions components in preschoolers with low and high quality of classroom interaction.

	Low CLASS level		High CLASS level		Mann–Whitney test
	Mean	St. dev.	Mean	St. dev.	U	p-value
Age	67.71	3.90	67.15	4.40	2,065.500	0.426
Non-verbal intelligence	14.11	10.09	14.44	6.95	1,997.000	0.337
Verbal working memory	19.48	5.44	18.90	5.11	1,935.500	0.216
Visual working memory	68.33	20.38	80.65	20.40	1,122.500	0.001
Cognitive flexibility	18.92	2.71	17.79	2.97	1,653.000	0.011
Naming uncorrected errors	0.70	1.23	0.47	1.08	1,688.000	0.025
Naming corrected errors	1.13	1.36	1.08	1.17	2,066.000	0.949
Naming time	45.51	13.10	43.17	9.37	1,835.500	0.251
Inhibition uncorrected errors	3.21	6.43	1.55	3.38	1,531.500	0.005
Inhibition corrected errors	2.08	2.24	2.59	1.97	1,669.000	0.050
Inhibition time	60.86	19.20	58.85	14.46	2,040.500	0.856