Job interviews often follow the path of (1) phone interview, (2) hiring manager interview, (3) hiring manager's boss interview, to (4) hired. This process works - if each of the people know how to interview candidates and have the technical knowledge of how work gets done in their department.
It doesn't work out that way all the time.
I had a manager who thought he did a great job interviewing (After all, he hired me so he must have excellent interviewing skills!). Instead, of the three people he hired in a couple of months, two of them were utter failures. (I was the grand success story. Of course.)
To his credit, he decided he was missing something in the interview process. From then on, whenever interviews came up he had two other people plus himself involved in the conversation. All the interviews were the same day. Candidates interviewed the three people serially. This was not done using the dreaded panel interview.
At the end of the day, the three interviewers got together. The manager always made the hiring decision with our input - sometimes over the strong objections of the others. But using this process, there weren't any more poor hires.
Why'd this process work so well?
Different People Discover Different Characteristics
People interview with their own worldview in mind. That creates blind spots for each of us. Having three people conduct interviews helps cover your blind spots while you cover theirs. This gives you a more complete picture of your potential co-worker and helps ensure the job skills are there to do the work.
The process also helps decide how well the person will fit with the manager and the team. This fit is important in determining team success, because matter how strong the candidate, hurting the team effort is a slow-moving train wreck.
Poor Perceptions Eliminated
When we interview, we develop our perceptions based on our questions and the candidate's answers. Those perceptions lead to the hiring decision. When a single person does the interviews, an incorrect perception is easy to create. But when three people interview, the incorrect perception is more difficult to create. In our post-interview discussions, one person would state a conclusion based on the interview, and the other two would say they didn't get that perception at all.
Then the questioning would begin: What did the candidate say to lead to that impression? What question did you ask that elicited the response? What was the body language of the candidate? What were the results in the candidate's answer from your question?
In other words, you need to form the candidate impression - and defend it. When you need to defend your impressions with others, you carefully ask questions and listen to the answers to get it right. Poor perceptions go out the window.
Good Feedback Builds Your Team
While candidates think the interview is all about them, a side benefit is that a candid, professional discussion between the three people at the end of the day builds teamwork. After all, you're not interviewing just one candidate one time. No, there are multiple candidates, so you do multiple interviews with the same three people to find the right fit for the department. This exchange of views between people builds the team, helps develop their job skills and supports meeting department goals.
The multiple face-to-face interviews, then, can go a long way toward identifying the right person for the position. For candidates, the process gets rid of poor perceptions from one interview, lets them showcase their business results to multiple people, and gives them a better shot at understanding the culture of the department.
-- Scot Herrick