Table 4.

Grade Point Average (Based Only Upon the Numerical Grades 1988-1997).

Cleft type	n	Cleft	Population	Mean t	z-test	P	Cohen d
Girls
CP	137	3.23 ± 0.06	3.37 ± 0.002	−0.25 ± 0.11	−2.29	.03	0.18
CL	143	3.38 ± 0.05	3.38 ± 0.002	−0.03 ± 0.11	−0.22	.38	0.00
CLP	173	3.19 ± 0.05	3.38 ± 0.002	−0.25 ± 0.09	−2.70	.01	0.23
Boys
CP	134	2.88 ± 0.06	3.10 ± 0.002	−0.29 ± 0.10	−3.04	0.004	0.29
CL	284	3.01 ± 0.04	3.12 ± 0.001	−0.15 ± 0.07	−2.04	0.05	0.25
CLP	297	3.08 ± 0.04	3.11 ± 0.001	−0.005 ± 0.07	−0.063	0.40	0.06