The independent t-test
- The independent t-test compares two means, when those means have come from different groups of entities.
- Look at the column labelled Levene's Test for Equality of Variance. If the Sig. value is less than .05 then the assumption of homogeneity of variance has been broken and you should look at the row in the table labelled Equal variances not assumed. If the Sig. value of Levene's test is bigger than .05 then you should look at the row in the table labelled Equal variances assumed.
- Look at the column labelled Sig. If the value is less than .05 then the means of the two groups are significantly different.
- Look at the table labelled Bootstrap for Independent Samples Test to get a robust confidence interval for the difference between means.
- Look at the values of the means to tell you how the groups differ.
- Report the mean difference and its confidence interval, the t-statistic, the degrees of freedom and the significance value. Also report the means and their corresponding standard errors (or draw an error bar chart).
- Calculate and report the effect size. Go on, you can do it.
Paired-samples t-test
- The paired-samples t-test compares two means, when those means have come from the same entities.
- Look at the column labelled Sig. If the value is less than .05 then the means of the two conditions are significantly different.
- Look at the values of the means to tell you how the conditions differ.
- Look at the table labelled Bootstrap for Paired Samples Test to get a robust confidence interval for the difference between means.
- Report the mean difference and its confidence interval, the t-statistic, the degrees of freedom and the significance value. Also report the means and their corresponding standard errors (or draw an error bar chart).
- Calculate and report the effect size too.
