[danpalmer]

> How do you know that interviewees aren't spending more time on it?

In some cases we roughly timed it, scheduling an email for a time the candidate wanted and asked them to return it 3 hours later. In some cases we just treated it as an honour system. We made it clear that the task was intended to take about that much time and that spending more time was not allowed/encouraged.

In reality, we found that good candidates took ~1-2h, and in some cases where candidates spent a lot longer and owned up to it, we found no improvements. In one case a candidate submitted at 3h and then again at 8, and we marked the 8h version 1 mark lower.