t-test for Independent Samples - Arrangement of Data

In order to perform the t-test for independent samples, one independent (grouping) variable (e.g., Gender) and at least one dependent variable (e.g., a test score) are required. The means of the dependent variable will be compared between selected groups based on the specified values (grouping codes, e.g., male and female) of the independent variable. The following data set can be analyzed with a t-test comparing the average WCC score in males and females:

 

GENDER

WCC

case 1

male

111

case 2

male

110

case 3

male

109

case 4

female

102

case 5

female

104

 

mean WCC in males = 110
mean WCC in females = 103

If you specified a list of dependent variables, then a series of t-tests will be performed (one for each dependent variable).