Three hundred programming interviews in thirty days

For example...

>The fizzbuzz-style coding problems, however, did not perform as well. While the confidence intervals are large, the current data shows less correlation with interview results. [...] The coding problems were also harder for people to finish. We saw twice the drop off rate on the coding problems as we saw on the quiz.

I read that paragraph several times and I don't understand what he's actually saying. If those candidates "dropped off" on the fizzbuzz, were they also still kept for further evaluation in the following extended coding session? A later paragraph says...

>So we started following up with interviews where we asked people to write code. Suddenly, a significant percentage of the people who had spoken well about impressive-sounding projects failed, in some cases spectacularly, when given relatively simple programming tasks. Conversely, people who spoke about very trivial sounding projects (or communicated so poorly we had little idea what they had worked on) were among the best at actual programming.

For the fizzbuzz failures to be non-correlative and counterintuitive, it means he did not reject them for failing fizzbuzz and they later ended up doing spectacularly well in the larger coding sessions. If that's what happened, then yes, that is a very counterintuitive result. What were the topics of the larger coding sessions?

They mention evaluating the effectiveness of giving a candidate a project to do "in their own time." I recently had a interview that included this and I can share the result: I accepted an offer from a different company that didn't require it. I doubt my life is that different than anyone else's, with a full-time job and a full-time life outside of work. Spending that much time to qualify for a single job is too much to ask of anyone. If it were to pass a generic proficiency certification applicable to many positions, I would consider it, but this does not scale if a candidate is applying for multiple positions.