Solved – Pre and Post test analysis utilizing a likert scale and SPSS

likertspss

I will openly admit that statistics and statistical programming is not really in my wheelhouse. That said, my job requires it. I am trying to analyze the data gathered from a pre and post test survey where responses were measured with a 1-5 likert scale. 1-strongly agree and 5 is strongly disagree. Essentially we would like to prove that our intervention changes attitudes closer to strongly agree for the majority.

I would like to be able to show the percentage of growth for each of our 14 questions from pre to post test. Essentially I need to know what is the change?

Again I am using SPSS and in way over my head.

Best Answer

I think you are looking for a test of equality of two proportions in paired data. A proper test may be the McNemar test.

http://de.wikipedia.org/wiki/McNemar-Test

In SPSS, you can check McNemar test under 'statistics' in the crosstabs dialogue. It will provide the proper test for a table using the pre/post measurement.

If you only want to test one proportion, you first need to recode the variable to an indicator variable, e.g. 1 vs. 4 to 5 (i.e., strongly agree vs. all other).