When I hire someone, like many people, I do reference checks. When I call a reference, I get one of three replies:
- a positive review
- a negative review
- a review of faint praise
If I get a positive review, it's generally a good reference. This is the review you want, where the reviewer is almost gushing and wants to work with the candidate again. Look for words and phrases like "great", "best", and "would hire again if this person hadn't moved across the country".
If I get a negative review, I'm almost never going to hire the person. A negative reference says not only that the candidate has caused at least some problems, but also that the candidate cannot properly pick a reference. This person is a potential problem in the workplace and has shown bad personal judgement. Run away!
If I get a review with faint praise, then I'm not likely to hire. Terms and phrases like "fine", "good", and "middle team member" aren't explicitly bad, but certainly point out that the candidate wasn't a great contributor. Keep in mind that the person giving the reference is someone that the candidate specifically chose to show how good the candidate really is. If faint praise is the best the candidate could get, again, that creates a lot of doubt about the candidate.
There are no hard-and-fast rules with reference checks. But keep an eye out not only for negative reviews, but also for a candidate who gets damned with faint praise.