Let's face it. Even if you're one of the best interviewers in the history of that scrum you call a company, odds are you've gone through periods where you just didn't feel like bringing your A-game to the table when interviewing candidates. It's OK, it happens to everyone who interviews a lot for a living. You're human.
The problem goes something like this: You've interviewed thousands of candidates, and those candidates tend to cluster around 4-5 basic skill sets, although you might have some slightly different flavors within those clusters from time to time. The limited diversity you see is the issue. You've done this so many times, you feel like you know whether a candidate is going to be a fit within 180 seconds, so after a while you start going through the motions.
Unfortunately, your human reaction to this dilemma means you'll never be as good in interviewing as you could have been, and here's why: When you phone screen 20 candidates and know within 180 seconds in each interview which 4 are the ones you're going to bring in to interview, you stop trying as hard.
Which means you stop giving valuable opinions to hiring managers on the 4 candidates you bring in for live interviews. That's a problem.
In my experience, if you are in this type of interviewing rut, there are 3 ways you can shake off the cobwebs:
1. Go negative. Use behavioral questions that ask for negative information (tell me about a time when you got fired or removed from a project. What the heck happened?) to stress the candidate and make it entertaining for you. You'll get great info as a result.
2. Get aggressive on the money side with the candidate. Find out what they need and ask them if they would take less, or what they could do to provide more value to your company and earn more. Nothing perks up the exchange better than a nice exchange about straight cash, homie.
3. Make the candidate think a lot more than they want to. Break out some questions that tell you how the candidate thinks and how they attack problems. You always learn from this type of exchange, whether the candidate implodes or waxes poetic for the next 15 minutes after you ask the question.
Need an example of how to make the candidate think? Try this story from Silicon Valley Insider about interviewing at Google:
"About ten minutes in, Oliver turned the tables. “I’m going to ask you a few questions that may sound strange,” he premised. I paused. Is there really any good response to a comment like that? He seemed to read my mind because he elaborated: “These questions are meant to test your analytical thinking.” Oh no. He was about to ask me the famous, ridiculously impossible Google questions I had been reading about on-line.
If you’ve never interviewed with the Internet giant, you may have never heard the types of questions they ask their interviewees. The searches I had done warned me that Google might inquire how much I’d pay someone to wash all of the windows in Seattle or what I’d do if I was shrunk to the size of a nickel and placed in a blender with churning blades.
“I want you to estimate,” Oliver began, “how much money you think Google makes daily from Gmail ads.” Oh. My. GOSH. Was he serious? The answer depended on so many different factors, none of which I had any clue how to guesstimate."
Click through and read the exchange for fun. The key isn't the answer, it's the depth of the explanation the candidate gives about why they would approach the problem a certain way. If you use the approach, look for the following two fail points: quick answers and little explanation for why related to your follow-ups for more information (they've given up and just want the bells to stop ringing), or a fifteen minute term paper that leaves you wanting a nap.
Hard on the candidate, but good for you to use to break out of your rut. Don't let yourself quit on trying to get the best information possible about every candidate - it's the only way you stay world-class as an interviewer.