t-test for Independent Samples - Alternative Arrangement of Data

Sometimes, the data are already arranged (e.g., as in a spreadsheet) such that each column or variable in the file represents one group:

 

Male

Female

case 1

111

102

case 2

110

104

case 3

109

 

Note that the Independent t-test option of the Basic Statistics and Tables module can also compute t-tests for data arranged in this manner. However, we should stress that this arrangement is atypical and generally not recommended when creating large data files. Practically all data analysis software, including STATISTICA, usually assumes data to be arranged as shown in Arrangement of data. The earlier arrangement allows us to identify each individual respondent or subject in the data file; thus, when there are multiple dependent variables of interest, various multivariate methods can be applied which rely on the (within-group) correlation matrices of variables.