They don’t. That is the conclusion from Google based on their own internal research. Some info from the New York Times article:
“One of the things we’ve seen from all our data crunching is that G.P.A.’s are worthless as a criteria for hiring, and test scores are worthless — no correlation at all except for brand-new college grads, where there’s a slight correlation,” Bock said. “Google famously used to ask everyone for a transcript and G.P.A.’s and test scores, but we don’t anymore, unless you’re just a few years out of school. We found that they don’t predict anything.
Mind you, this is research from inside Google – they know a thing or two about data analysis. I’ve told many hiring companies that GPA’s just don’t matter in the real world, especially for sales hiring. Give me a street savvy, strong qualifying salesperson any day over a book smart, ivory tower salesperson. It is best to find candidates that fit both criteria, but GPA is not a reliable predictor of future success.
The feedback from Google’s research on the best strategy for successful hiring (emphasis mine):
Bock said it’s better to use questions like, “Give me an example of a time when you solved an analytically difficult problem.” He added: “The interesting thing about the behavioral interview is that when you ask somebody to speak to their own experience, and you drill into that, you get two kinds of information. One is you get to see how they actually interacted in a real-world situation, and the valuable ‘meta’ information you get about the candidate is a sense of what they consider to be difficult.”
Yes, drill down is what we like to call it. I believe it is the single most important interview skill – you must be able to drill down on responses to peel back the veneer and get to the core of the candidate’s response.