The Contribution of Using Cooperative Learning Methods on Students’ Achievement and Retention in Secondary Schools during Chemistry Lesson

Table 2

Contribution of training to the experimental group of students’ chemistry achievement (N = 64).

Tests	Mean	SD	95% confidence interval of the difference		t-Value	df	p-Value	Cohen’s d
			Lower	Upper
Pretest	27.88	5.884	−45.753	−39.091	−25.45	63	0.000	0.91
Posttest	70.30	10.471

Mean difference is significant at