b. Results of the effect size analysis 

     The results of the effect size analysis are shown in the following table. The effect sizes of the first and second tests in Bayankhongor province are 0.779 and 0.378. The median effect size was 0.56. The effect sizes of the first and second tests in Ulaanbaatar city are 0.537and 0.708. The median effect size was 0.62.