Table 8: Independent samples -test of posttest results for two groups.

 Levene’s test for equality of variance -test for equality of means
      Sig. dfSig. (2-tailed) Mean differenceStd. Error Difference
LowerUpper

Equal variance assumed1.584.219−12.55328.000.000−15.800001.25862−18.37817−13.22183
Equal variance not assumed−12.55326.276.000−15.800001.25862−18.38581−13.21419