Sometimes a researcher begins with an ASCII file created manually or by optical scanning. An ASCII data file should have lines of no more than 80 columns with all the data for the first participant followed by all the data for the next participant and so on until all the data has been entered. Each case or participant should begin with a new line and each variable should be in the exact same location for each participant. For example, biological sex may be coded in the first line, fifth column for each participant. There are other ways to format data for SPSS input but this is the most common and probably the most useful.

To convert the ASCII file to an SPSS file, click File > Read ASCII Data... and select the appropriate file. Then click the Define button and a window will open that will allow you to specify the name and exact location of each variable. "Record" refers to the line of data. After completing all four boxes click ADD and go to the next variable, continuing until all variables have been defined. Then click OK and the window closes showing the spread-sheet with all the data read into it. Whether you have started with an ASCII file or entered data directly into the spreadsheet, the data file can be saved as an SPSS file that can be recalled at any time. The save operation should be repeated each time the file is permanently changed. I suggest that you maintain at least two backup copies, one which travels with you and a second which stays in a secure location.