|
Compute
Function
(summary or total scores)
Task: Using the Computer Function to create a new
summary variable (e.g. total scores) from a group of
variables.
Start off by importing the
ex3reverse.sav
into the Data Editor window of PASW / SPSS (from this point forward
referred to as simply SPSS). If you would like a more detailed
description of our example data and the fictional situation behind it,
please review (Module
4.3).
The compute function can be used to sum a series
of variables such as items of a subscale on a survey.
For the example below, we will be computing a
total score for our 6 item survey.
To use the Compute function, simply go to
"Transform", "Compute Variable..."
You should now see the "Compute Variable" dialog
box.
In the Compute dialog, first type Total_Score in
the "Target Variable:" box which will be the name of our new variable.
Then, type the equation in the "Numeric Expression:" box, or you can
move each variable one-at-a-time and click the "+" button on the
calculator pad with a space before and after each "+" to construct the
equation. Now just click on "OK" or "Paste" if you would prefer a
syntax record be created (from which you can highlight and submit the
syntax to perform the compute/recode). Remember, it is often quicker to
write the syntax for simple compute functions than it is to navigate
through and point-and-click to complete the function. A review of the
syntax from this example (provided in the Log portion of your output)
will show how simple it would be to write such syntax.
That concludes using the Compute function to
create a new variable as a sum or total score of a combination of
variables.
|
