So you are supposed to provide data sources about problems, but are not allowed to involve opinions in that? Can you give some examples of feedback that would fit that criteria?
- My boss doesn't like me and excludes me. vs - I think my boss has a few favorites who get all the cool projects. Despite me being the best person as I had the most experience with technology X, my performance in good standing, and having showed interest in the project, I didn't get assigned to that project.