Post by neurology admin on Feb 21, 2013 3:22:07 GMT -5
What it does: The Independent Samples T Test compares the mean scores of two groups on a given variable.
Where to find it: Under the Analyze menu, choose Compare Means, the Independent Samples T Test. Move your dependent variable into the box marked "Test Variable." Move your independent variable into the box marked "Grouping Variable." Click on the box marked "Define Groups" and specify the value labels of the two groups you wish to compare.
Assumptions: -The dependent variable is normally distributed. You can check for normal distribution with a Q-Q plot. -The two groups have approximately equal variance on the dependent variable. You can check this by looking at the Levene's Test. See below. -The two groups are independent of one another.
Hypotheses: Null: The means of the two groups are not significantly different. Alternate: The means of the two groups are significantly different.