3.4 Effect Sizes

Effect sizes were calculated using a method that takes pretest scores into account by subtracting the effect size of the comparison group gain from the effect size of the experimental group gain, using pooled standard deviations (Rudner, Glass, Evartt, & Emery, 2002). Table 8 presents the effect sizes between the groups. Note that the group that wrote in Japanese was superior to all other groups in five out of six comparisons. (A plus sign indicates that the first group of each pair was superior.)

Table 8. Effect Sizes

JSG= Japanese summary group
ESG = English summary group

3.5 Pages Read

The groups read about the same number of pages during the first and second semesters, but in the third semester, the Correction group read more than the other groups (Table 9).

Table 9. Descriptive Statistics for Number of Pages Read

JSG = Japanese summary group
ESG = English summary group

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