That's actually how I conduct interviews. It's been immensely successful at weeding out candidates within 5 minutes; although most interviews are 45 - 60 minutes.
Basically, give them less than ten lines of code, ask them what it does, where are a couple bugs, ask what would you name the function, etc. Then we talk about how to improve it. I'd say, less than 20% of people I interview pass. It's actually amazingly low how many people can find a bug and communicate it.
Half the people don't even tell me what they are thinking. And no matter how many times I try to work with them, act like their buddy, or w.e. they just kind of shut down. They think in their head, don't work through the problem at all.
Basically, give them less than ten lines of code, ask them what it does, where are a couple bugs, ask what would you name the function, etc. Then we talk about how to improve it. I'd say, less than 20% of people I interview pass. It's actually amazingly low how many people can find a bug and communicate it.
Half the people don't even tell me what they are thinking. And no matter how many times I try to work with them, act like their buddy, or w.e. they just kind of shut down. They think in their head, don't work through the problem at all.