Table 3.

ANCOVA tests of between-subjects effects at post-test for writing performance.

Source	Type III Sum of squares	Df	Mean square	F	p	Partial eta squared
Corrected model	9,154.694a	3	3,051.565	30.361	<0.001	0.302
Intercept	20,936.195	1	20,936.195	208.302	<0.001	0.497
Pretest	8,192.335	1	8,192.335	81.509	<0.001	0.279
Group	809.980	2	404.990	4.029	0.019	0.037
Error	21,207.337	211	100.509
Total	1,260,601.250	215
Corrected total	30,362.030	214

^aR² = 0.302 (Adjusted R² = 0.292).