This attached page gives a pretty straightforward path to using the Kolmogorov-Smirnov and Shapiro-Wilk tests for normality within the SPSS program. Since I would be just rehashing what is written on the site, I will just attach the link.

https://statistics.laerd.com/spss-tutorials/testing-for-normality-using-spss-statistics.php

If this proves to be problematic please respond back and I will take a closer look at any specific issue you may be experiencing.

Logan Netzer

Hi Logan,

Many thanks, unfortunately I have already read this article but I'm looking to compare 2 samples distributions with each other instead of testing their normality.

I did found many tutorials on how using the KS test for 1 sample but I'm still looking for a procedure that could allow me to use the Kolmogorov smirnov test on 2 samples. I'm usually using this online KS test (http://www.physics.csbsju.edu/stats/KS-test.n.plot_form.html), but my 2 datasets are exceeding the maximum number of values per condition to be handled online.

Alright, so you have two samples, did you try to combine thing into one sample with a flag variable that separates them? What I am saying is make both samples one variable, then create a second variable coded as 0 for the first sample and then 1 for the second sample and then add the two distributions combined into one variable and have them grouped by the flag variable. I don't have SPSS anymore so I would just do it for you. I have altered your excel file to show what I mean.

So for the explore option, you would put the populations variable (the combination of the two variables in the dependent list and then use the flag variable (coded as 0 or 1) in the factor list. Have you tried this?

If this is still a problem you could use R if you are familiar. And if not I would be willing to run it for you.

Logan Netzer

so using the shapiro-wilks test for normality the first population could be considered normally distributed but the second population would not.

Dear Logan,

Thanks a lot for your help ! That is working perfectly fine for me now, I knew that the distributions were different I was just missing a p value. But with your help manage to run the test on SPSS.

Many thanks !

Laura

Hello Laura Le Gall Logan Michael Netzer ,

Greetings.

I saw your conversation on kolmogorov smirnov in this forum and me too facing ambiguity in understanding as there are no clear videos in YouTube. Kindly help me out.

My 1st independent categorical variable is gender (male and female) and another variable dependent one is humor on ordinal scale anchored from 1 to 4 (1 – extremely serious, 2- moderately serious, 3- moderately funny and 4- extremely funny).

What test in K-S I should do? One sample or two sample and also the random videos on K-S doesn’t give D values. Kindly help me put.

Thanking you.