I am planning a meta-analysis on reliability of various loneliness scales. We want to determine beforehand what time frame between measures we will consider.
For instance, if the time between 2 measures is 2 years (such as in some longitudinal papers), we would consider this to be an indication of rank-order stability rather than test-retest reliability. This is a clear case, but what about 3 months? Or 1 month? Where should be the limit?
We are looking for good resources to base our decision on, and would be glad with any advise.