卡方值

Sig.

事后检验

词汇覆盖率95%

15.455

0.001

1 = 2; 2 = 3 = 4; 1 < 3, 4

词汇覆盖率98%

13.339

0.004

1 = 2 = 3; 2 = 3 = 4; 1 < 4