It's often said that the first five minutes of a job interview are the most important. That is when, we are told, the interviewer forms their opinion of the candidate and makes their decision about whether or not to hire them. For the rest of the interview questions will simply be used to confirm this initial snap decision. But is this really a good way to assess whether candidates are a fit for your company? Google certainly doesn't think so; the tech giant said goodbye to traditional interviews several years ago and has been using structured interviews ever since. What's more, Google has been monitoring the quality of their hiring decisions, and the data shows that the change from unstructured to structured interviewing techniques has lead to a dramatic improvement.

So what exactly is a structured interview? The name holds a clue: it's an interview in which every candidate is asked the same predetermined questions, and graded on their responses. The questions are carefully designed and come with set criteria for correct and incorrect answers. This does away with open-ended, non-specific questions like "What's your greatest weakness?" or (even worse) novelty questions like, "If you could have a superpower, what would it be?" The interviewer doesn't improvise, or ask unplanned questions. Everyone faces the same interview and is graded fairly on their responses.

The result of structuring interviews in this way is significantly better hires. Laszlo Bock, former Senior Vice President of People Operations at Google, states that the average interview can only give you insight into about 14 percent of a prospective employee's performance. Structured interviews, on the other hand, can explain up to 26 percent of their ability - almost double the result.

So why hasn't every company followed Google's lead and instigated structured interviews as standard? Why are candidates still routinely asked irrelevant, open-ended questions no matter what job they're applying for? Part of it may be that research has shown that interviewers are generally convinced that they're already great at interviewing, even if they're not. Part of it may also be that designing a structured interview is hard - it takes time and effort to come up with great questions, and train interviewers to stick to the script. Given the degree to which it improves hires, however, more and more companies are deciding that it's worth the time and energy - and the Office of Personnel Management even provide some free resources to help your organization make the transition.