Transform → Compute Variable is a function specific to SPSS that allows its users to modify data set variables into calculations specific to their mathematical needs. In using compute variable, data sets are able to be modified into formulas generating results such as total sums and averages. Compute Variable can also be used in situations such as Using CDF NORMAL and IDF NORMAL. The Transform → Compute Variable is an integrated calculator that allows for easy computations of data without having to export or use other devices to compute desired functions.

For instance, Mrs. Calvin is an 8^th grade math teacher in Utah who is interested in comparing how her student’s tests scores correspond to nation scores by state.  Currently, Mrs. Calvin’s students have an average math test score of 275 over the course of the last 5 testing periods. After researching data sets from the National Center for Education Statistics, she was able to export data files by state for the years 2005, 2007, 2009, 2011, and 2013 below is the data that she collected.

In order to extract averages, maximum, and minimum test scores for the last 5 testing periods, Mrs. Calvin will utilize Transform → Compute Variable in SPSS below we can see the averages and maximum test scores.

How to Use Transform → Compute Variable in SPSS

• Click on the "Transform" menu at the top of the page and then click on "Compute Variable".
• When the pop up window appears, enter a name under “Target Variable”.
• Select “Function Group” that correlates to your calculation then click on the “Function and Special Variable”, again selecting the function that matches your calculation.
• Your function will now appear in “Numeric Expression” and enter inputs that corresponds to the “?” mark. At the bottom of the pop-up window, an explanation text box will appear with support for data input.
•  Click "OK" at the bottom of the screen and the “Target Variable” calculations will appear in the SPSS spreadsheet alongside your existing data.