kruskall-wallis analysis problem
Hello, I'm here to ask for your kind help.
I would like to ask you a couple of questions:
1) I need to test the differences between two independent groups (young and adult) for x-rays abnormalities of the thoracolumbar tract (14 spaces each). Data are ordinal, so I supposed to run the Kruskal-Wallis test to test if a difference occurs in the two group. I didn't choose the two-way independent ANOVA because that test looks for the effect of the parameters on the variable. Is it correct??
2) I tried to run the Kruskal test but once added the factors the bar display an error: residual df = 0 (in attach you will find a screenshot). How can I manage this error? Do you have any suggestion to how to organise the row data (in attach you will find a screen of mine dataset)?
Thank you very much for any help, hope to hear from you soon.