In the Oneway platform, the t Test report summarizes the results of a t test to compare two group means assuming either equal or unequal variances across groups. This report is available only when the X variable has exactly two levels.
The t Test or Pooled t Test table lists the difference used and the variance assumption. The report also contains the following statistics:
Difference
The estimated difference between the two X levels.
Tip: Use the Value Order column property to change the order of the differences.
Std Err Dif
The standard error of the difference.
Upper CL Dif
The upper confidence limit for the difference.
Lower CL Dif
The lower confidence limit for the difference.
Confidence
The level of confidence (1-alpha). To change the level of confidence, select a new alpha level from the Set α Level option from the platform red triangle menu.
t Ratio
The t-statistic.
DF
The degrees of freedom used in the t test.
Prob > |t|
The p-value associated with a two-tailed test.
Prob > t
The p-value associated with a one-sided upper-tailed test.
Prob < t
The p-value associated with a one-sided lower-tailed test.
t Test plot
Shows the sampling distribution of the difference in the means, assuming that the null hypothesis is true. The vertical red line is the observed difference in the means. The shaded areas correspond to the p-values.