I've probably done 50 interviews and hired around 10 people. The people doing them with me and I used a decently uniform process to give all applicants the same set of quite varied questions. We also gave the interview process to a decent number of existing employees to see how an existing employee fares.

I started the process thinking education would be quite independent of performance. Our data from the process showed exactly the opposite.

Quality of education, especially at entry level, made a large difference in the process and also in the long term performance of the hires.