Fred Wilson, founder of Union Square Ventures, says every CEO should conduct exit interviews. 

"I have learned more doing exit interviews than most other management techniques," Wilson wrote on his blog, AVC. "When people are on their way out and have no fear of saying exactly what they think, you can learn a lot."

But what should leaders look for in these meetings, really? Wilson says to seek patterns, which will become more evident with each passing interview. If you can pinpoint the pattern, you can pinpoint the reason your workers are leaving. Then you can come up with a plan to keep those who've stayed.  

Here are some other guidelines Wilson recommends.

Find the cause.

Context is everything when you're trying to figure out why someone is leaving. They may state their reasons, but you need the whole picture, especially if things are tense. Make sure to speak with their manager and every party involved to get a true sense of their environment and why they left.

Don't be confrontational.

An exit interview isn't a "witch hunt." Make it an ongoing conversation about the good and bad aspects of your company, its operations, and staff. Be calm, don't get aggravated. "The less confrontational the exit interview is, the more you can learn," Wilson writes.

See both sides.

Everyone has his or her own opinions, experiences, and perspectives. Don't take everything they say "as gospel," especially if you hold this employee in high regard. Once you know the context, make sure you can see both sides and have a balanced conversation. As Wilson warns, everyone has an agenda. They could be leaving to prevent themselves from getting fired down the road, so don't let them dupe you during the interview.