From Laszlo Bock, former SVP of People Ops @ Google.
> [1] The best predictor of how someone will perform in a job is a work sample test (29 percent). This entails giving candidates a sample piece of work, similar to that which they would do in the job, and assessing their performance at it.
Based on the statistics he provided, it seems like a combination of work sample and behavioral questions will typically produce the best results.
The problem is that Google gets ~2 million applications per year, so there needs to be an aggressive, quick funneling process. If you're a smaller company, you can definitely afford to slow down and give candidates more of a chance.