[lmilcin]

You are hiring somebody who will be managing managers meaning they will probably have responsibility for at least dozens if not hundreds or even thousands of people.

As a manager/leader of that organisation they will have an important role that can mean difference between those hundreds of people bringing huge value or huge loss to the company.

So your responsibility is to figure out how much time to spend with the candidate. You can choose anywhere between "just hire first person to apply" and "spend a year grooming an employee to see if they can do the job".

And you want to tell me that 20 minutes is the right answer here? That out of entire continuum of possible choices you say that the optimal return (performance of manager) on investment (cost of conducting interviews) lands at approximately 20 minutes -- less time than you take to have a lunch?

I get that he had couple of these sessions but still... it sounds like giving the job to a first person that looks the part.

[tzs]

What I'm suggesting is that maybe what matters is the total set of questions asked by all the interviewers. Does it really matter if one person asks questions for 2 hours as opposed to 6 people asking questions for 20 minutes each if the same questions are asked?

The former gives more flexibility to alter the questioning on the fly, such as to delve more deeply into some area than had been planned. The latter gets more people to spend time with the candidate.

A mix of this could be the best of both worlds. Have several short interviews mixed with some long ones. If one of the short ones turns up something that seems worth going in depth on that can be handled in one of the long interviews.