[jerf]

Well, I can say on the flip side I've been involved with hiring decisions where the interviewee did not nail every single answer, but we hired anyhow.

It should be pointed out that I structure the interviews to try to avoid that case anyhow. If your interviewee nails everything, it either means that you've got a class-A programmer, or your interview difficulty tops out too soon. I've become a big believer in gradated interviews. I've got a pretty good SQL series that starts out where the answer is literally "SELECT * FROM some_table" (though I find it occasionally trips people up to simply omit the where clause) and goes up from there on this little two-table schema. I've got some good HTML generation series that starts out with a simple "can you dump out a table from a 2D array or equivalent structure?" (since I try to do language-agnostic interviews) and go up through "do you know about escaping" and "can you handle optional parameters" and so on. Over time I've been selecting for the series that produce more gradation.