How to enter missing data in SPSS
It’s likely that your data set will contain some missing values, where participants didn’t answer some items
on a questionnaire or didn’t complete some trails in an experiment.
1.
When you initially enter your data, leave any missing values as blank cells.
2. To get SPSS to fill in all the empty cells, go to Transform – Recode into Same Variables.
3. Move all your variables into the right hand box and click on Old and New Values.
4. On the left select System- or user-missing and on the right enter a number that will not otherwise occur
in your data set (eg. -9999) in the ‘New Value’ box. Click on Add, then Continue. Click on OK.
5. All blank cells will now be replaced with the value you entered in the previous step.
6. So that SPSS doesn’t include these numbers in any calculations you must complete one final step. Go to
the Variable View.
7. The eighth column from the left is called ’Missing’. Click on the first cell under this column, and click on
the blue box that appears in the cell.
8. Select Discrete Missing Values and enter in the box the number that you chose in step 4. Click OK.
9. Repeat steps 7 and 8 for every row in the variable view (You can copy the first ‘Missing’ cell and paste
into all cells below to save time).
N.B. If you are computing total scores please consider the impact missing values will have on this calculation.
It might be more suitable to calculate mean scores instead based on the number of answers you have for
each participant. Alternatively, some questionnaire manuals advise replacing missing values with the
participants’ mean score before calculating a total score.
Charlotte Elwell | 2012
(SPSS v.18)