It is possible to anonymize your survey data after you have carried your survey out. This may be particularly useful where you want to continue to work with your survey data, but don’t need to keep hold of it in a form which still identifies your respondents.

Snap stores respondent data in a file with the survey name and extension .rdf (respondent data file). Replies for each respondent are held in individual records in that file. When you delete the variable that holds the personal information from the survey file (.mdf), the details remain in the data file. It is possible to remove the personal data entirely.

Summary of steps

Step 1: Back-up the survey
Step 2: Use the bulk change feature
Step 3: Check the data to ensure your changes are correct
Step 4: Delete the back-up

Step 1: Back-up the survey

At the Survey Overview, highlight the appropriate survey and choose File | Archive Survey. Ensure Include Raw Data is ticked | click Browse and choose a location to save the archived file | click Save | click OK.


Step 2: Use the bulk change feature

Open the survey.

Click multiples icon to open the Variables window and scroll down to display the variable you are interested in (Q1 in this example).

Click the Tailor icon Tailor Icon on the toolbar to tailor the Variables window.

In the Variable Tailoring window, tick Source and click Use.

Note the source position for the variable you wish to change (834 to 933 in this example).


Click Data Window to display the survey Data Window.

Click Arrow on the Data window toolbar to display the Bulk Changes dialog box.


The Filter field is used to select the data codes to be changed or to exclude the ones that you do not want to change. The Change field is used to enter the new data. The new data must be surrounded by quotation marks.

Set Filter to Q1 ok this filter finds all valid responses to Q1. Set Change to raw (834 to 933) as “ “ to change the values in position 834 to 933 in the raw data file to a space character.

raw tells Snap to make the changes in the raw data file. (You could also use * (834 to 933) as “ ”).


Click [OK] to make the changes.

Repeat Step 2 above for all variables containing data you wish to remove.

Step 3: Check the data to ensure your changes are correct

This can be done via the Data Window Data Window by scrolling through the cases or filtering. It can also be done via the analysis icons or reports.

You should now have a file with the personal data removed.

Step 4: Delete the back-up

Locate the Archived survey file you created in Step 1 above, archived files have the .adf file extension and delete it.

Remember if you have made backups to your own systems they will also need to be deleted.

You should also familiarize yourself with the Snap file structure to ensure you don’t have any other files on your system that may contain personal data.

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