I’ve worked in H/R and you’d be surprised the things I heared from references. I used to think “Why would they put down someone who would give them a bad reference.” Well it happens.
A lot of times industry is very closed mouthed. When I worked in the hotel industry in Chicago, several times I got a decent reference only later to have the someone else from the place he worked call back and say “Mark this is off the record, don’t hire him.”
On the flip side, my last employer has a policy of only giving out start dates, end dates, if you gave notice and they will confrim salary (they won’t give it out, they will just confirm whether or not an amount is correct).
When I applied at once place, I went through six interviews and the H/R guy said “Mark we HAVE to have a real reference, if you can’t give me a name from that place, I can’t hire you hire.” I gave him a few names but they all referred the guy to H/R (as was company policy, only H/R gave out references).
The thing is though, after working in H/R there are all sorts of ways to give bad references without directly doing so. A lot of companies now use only faxed requests so they will have a written documentation of what was written down.
On the flip as an interviewer, what I do is in a round about way ask for their supervisor’s name. For instance I might say "Oh yeah I know her, I worked with her. You’re supervisor is Mary right? And he’ll say “No, it’s Wendy,” and I’d come back, “Hmm, must be thinking of someone else.”
So then I could call up Wendy and ask her directly, if I was suspicious.
But now-a-days, companies go bankrupt, the merge, etc so it’s often hard to find people.