You've gone through the hard process of hiring. Countless interviews, hours of pouring over resumes, and you've finally found the one! Most managers at this point are chomping at the bit to make the offer. However, it's a huge mistake to skip one last step- reference calls.
Why? Well, there are countless horror stories out there on the internet of managers who discovered that their dream employee was actually a convicted embezzler or quit their last job in a flourish of sabotage. However, on a less dramatic scale, talking to references gives you valuable insight into how employees actually behave in the workplace. So far, all you have to go off of is the word of your potential new superstar. We all want to think the best of ourselves though. Talking to a former manager can give you a sense of what it's really like to work with this employee.
I'd also advise avoiding an emailed questionnaire. You get a lot more context from a phone call than you do an email. The reference's tone of voice and inflection can give you insight that you may have not gathered otherwise. It also gives you the opportunity to ask follow-up questions and probe deeper into the comments they made.
My favorite questions to ask references include:
join the book club