From Lou Adler:
More than 90 percent of hiring managers think they’re good interviewers, yet rarely do they reach unanimous hiring decisions with other 90 percenters in the same room evaluating the same candidate. This realization led me on a quest to find the one interview question that would yield universal agreement from hiring managers. It took 10 years of trial and error, but I eventually found it. Here’s it is:
What single project or task would you consider your most significant accomplishment in your career to date?
Lou then asks detailed follow up questions, such as “Walk me through the plan, how you managed it, and its measured success”, “How long did it take?”, “What were the actual results?”, “What aspects did you love, and what didn’t you enjoy?”. He concludes:
With an accomplishment big enough, and answers detailed enough to fill 20 minutes, this one line of questioning can tell an interviewer everything he or she needs to know about a candidate. The insight gained is remarkable. But the real secret ingredient is not the question; that’s just a setup. The most important elements are the details underlying the accomplishment. This is what real interviewing is about — delving into the details.