Comparing 2 groups? Independent sample t-test

Independent sample t test is used to compare the means of two separate, or unrelated groups to see if they are significantly different.

When conducting an independent sample t-test, you need a dependent and independent variable. Your dependent variable must be continuous. An example of a continuous variable is age or test score. The independent variable is categorical with two levels only. An example is Gender with male and female.

Additionally, the following assumptions must be satisfied: One, the observations in each sample must be independent of each other. This means that the data from one group must have no influence on the data from the other group.

The second assumption is that the variance from both groups should be approximately equal. This is also called, homogeneity of variance.

Finally, the dependent variable should be normally distributed within each group.

In summary, use independent sample t-test when you want to compare the mean of two unrelated groups. Remember to always check assumptions before doing the statistical test.