Table 1.

One-sample t-test results on the management of free-riders.

	Test value = 3
	Items	X	t	p	η2
1	I make an individual share of tasks of the group work clear	2.90	-.88	.38	--
2	I make each student responsible for a certain section of the group work	3.25	1.94	.054	--
3	I make sure division of labor (roles) upon tasks for each group member	2.67	-3.2	.002	.07
4	I make students know they are jointly responsible for the entire work	3.76	7.34	.000	.27
5	I make students warn free riders to contribute their share	3.58	6.25	.000	.21
6	I ask students to report group members who fail to contribute their share	3.60	5.58	.000	.18
7	I make sure equitable and fair distribution of tasks and individual	3.23	2.64	.009	.05
8	I form small heterogeneous groups most of the time	3.69	6.67	.000	.23
9	I make the group to assign group leader and secretary	3.92	9.50	.000	.38
10	I go round and monitor group work	3.72	7.56	.000	.28
11	I assist and encourage students while working the group work	4.03	11.9	.000	.50
12	I orient each group to have unity and team spirit	3.82	10.2	.000	.42
13	I specify the contribution required of each individual	3.26	2.01	.046	.03
14	I encourage students not ‘to ignore their colleagues’ carelessness	3.56	6.27	.000	.21
15	I support and make a follow-up of the group to reduce free-riding	2.90	-.84	.403	--
	Sub-scale	3.46	5.49	.000	.17