When interviewing job candidates, how many interviews should you conduct?  There is clear evidence that shows that assuming the same criteria and an organized approach, two interviews are dramatically better than one.  It is much better for two interviewers to see the candidates for 45 minutes than for one interviewer to spend 90 minutes with the candidate.

For that matter, three interviewers are better than two.  The increase in the accuracy of judgment is not as great as in the going from one to two, but it is better by a significant margin.  Four adds a small gain in accuracy.

The most common model is this: the first interviewer is a professional in the Employment, Personnel, or Human Resources department.  He or she may set the schedule for the day and/or be the last interviewer to see the candidate.  Issues such as relocation and benefits may be covered by this interviewer.  In instances where the HR interviewer starts the hiring process with an initial screening interview, a decision might be made at this point for the candidate not to go on to others.  Of course, if there’s a chance of tha happening it would be better not to lead the candidate to expect four interviews, but rather to tell him that other interviews may take place if the manager of supervision is “available.”

In most cases, any more than four interviews will not increase the accuracy of the judgment nor will it add much to your ability to influence a candidate.  There may be political reasons why six or seven people have to see a candidate.  It may be that two people in each of three departments have to “sign off” on the candidate – that’s six right there.  But from the standpoint of decision making and the ability to influence the candidate, it is inefficient to go beyond four.  Even when many people see a candidate, a formal interview might not always be necessary.