We're currently planning an experiment and wondering whether this should be regarded as repeated measures. (And more generally, where the boundary between repeated measures and non-repeated measures is.)
In the experiment, subjects are asked to find defects in two work-products (in counter-balanced order). One of four treatments has been applied to these work-products, and we are interested in differences between the treatments. The number of defects is the dependent variable.
We assume that the number of found defects depends on the subject and therefore that each subject's result for the first and second work-product are correlated, which would indicate repeated measures. But the number of found defects probably also depends on the work-product, so in a way we have different measurement instruments and therefore no repeated measures. So should we use a test for repeated measures?
Taking this a bit further, we consider measuring some covariates per subject, build a regression model and analyze the residuals (ANCOVA?). This will decrease the correlation between subject and defect residuals. So if it was repeated measures in the first case, will it still be repeated measures here, too?