Table 3 Change in the students’ intrinsic motivation in the EG between the control lesson (Post-Questionnaire 1) and the first experimental lesson (Post-Questionnaire 2_1) (Wilcoxon signed-rank test)

Md of EG in control lesson (SD)

4.57 (1.50)

4.00 (1.39)

4.50 (1.25)

4.57 (1.31)

Md of EG in first experimental lesson

(SD)

5.86 (1.23)

4.20 (1.27)

4.83 (1.08)

5.86 (1.31)

N of control lesson

267

267

267

267

N of the first experimental lesson

257

257

257

257

Number of comparisons

220

220

220

220

Z

− 9.750^a

− 2.822^a

− 4.189^a

− 9.559^a

p-value (2-tailed)

0.000*

0.005*

0.000*

0.000*

Cohen’s d

1.051

0.273

0.408

1.025

Hedges’ g

1.049

0.273

0.407

1.023