From: Controlling item difficulty for automatic vocabulary question generation
 | G1 | G2 | G3 |
---|---|---|---|
Number of students | 31 | 28 | 29 |
TOEIC avg | 606.33 | 594.07 | 596.42 |
 | (SD: 166.11) | (SD: 170.81) | (SD: 178.37) |
Test score avg | .496 | .471 | .581 |
 | (SD:.1) | (SD:.1) | (SD:.09) |
TOEIC-Test score corr. | .693 | .612 | −.09 |