I'll describe my research and then I'll ask the question;

I have 30 Schools, that in each a group of teachers answered a questionnaire: "PII", as well as the principal.

I want to test the correlation between the teacher's PII mean and THEIR principal's PII mean. I need to test it in each school SEPARATELY. Meaning, I basically have one group of teachers with a PII mean and SD, and ONE principal with PII mean and no SD (because I have only one principal in each school).

How can I test it ??? I can't perform, obviously, a standard simple r correlation, because of the principal's SD is =0.

*Again, I can't consider all the principals as one group, I have to test it in each school separately.

Any ideas please??

Thank you !

Yaara