1. Under Data tab, Select Merge to display the Merge Options dialog. 

To merge variables(columns of data, the second file can be appended to the "right side"):

2.Select "Variables" tab and select "Mode" to define how variables are merged:

"Concatenate": simply add the variables of the second file to those of the first (this is the default mode);

"Cartesian": create a cross product of the variables;

"Match casenames": match the cases from the second file with those of the first file based on the case names;

"Match variables": match the cases from the second file with those of the first file based on the values of specified variable pairs. To specify the matching variables in each data file via the "Select" button; Cases are merged only if their respective values match. Note that missing data is ignored.

3. Select an option through "Unmatched cases" to specify the manner of dealing with unmatched cases when the two files are merged

4. When either the Match casenames merge or Match variables merge options are selected in the Mode group box, the options in the Multiple Cases group box become available to specify what to do if duplicate matching cases are encountered.

5.Click "File 1..." and "File 2..." to select the two spreadsheets need be merged.

To merge cases(rows of data, the second file can be appended to the "bottom"):

2. Select "Cases" tab and select "Mode" options to specify how Statistica should append the new cases from the File 2 data file into the File 1 data file.

3.Select "Text Labels" options to specify how Statistica should handle numeric-text assignment conflicts when merging two files.

4.Click "File 1..." and "File 2..." to select the two spreadsheets need be merged

Note: Click "?" on top right of each tab in the "Merge Options" dialog to learn more details of each session in e-manual.