It seems to me that in most positions you should be able to get a decent feel for the technical abilities of a person based on the first hour or so of an interview, along with their resume, reference, and maybe a technical test. So what benefits does a company reap when it spends several man days worth of their employees time to keep them occupied all day long in an interview. The interview process is costly enough with out making it longer than needed.
So why is it that many companies have shifted to a day long(sometimes more) interview for professional positions? There must be some benefits that are consistently noticed for companies to make this shift. What are they?
( 7 months ago )
In many cases, the reason to have full-day interviews is to give multiple individuals the chance to interview the candidate. That could be multiple members of the technical team. It could be members of teams that the candidate would be working with regularly. It could be a couple levels of management. So while one person can probably determine how technically proficient a candidate is after an hour or two, if you want a couple of different opinions, it can easily take a full day of interviews.
Getting multiple perspectives on a candidate serves a variety of purposes. When many people have a hand in the hiring decision, many people have a stake in the success of the candidate that is hired. When the role involves interacting frequently with different teams, getting buy-in from those teams can smooth over initial growing pains. It can also make the team that will be working with the candidate feel like they have more control over the people that they're going to be spending their days working with. When many people have a hand in hiring a candidate, it is also possible to identify more problems than one interviewer alone can identify. Sometimes a candidate gets along well with one interviewer but would not work well with other members of the team-- perhaps the candidate seems to get along well with men, for example, but doesn't relate well to women. Determining this in advance by having the candidate interview with a woman on the team is obviously less expensive than trying to resolve the inevitable interpersonal conflicts that would arise. Google, for example, has found that it takes four interviews for a candidate's score to converge on their final score. Additionally, multiple interviews can help a company maintain a particular culture since different interviewers are likely to be attuned to different aspect's of the candidate's fit.
Spending a full day at the company also has benefits for the candidate. It gives the candidate the opportunity to meet with many different people they'll be working with and get many different perspectives on the position and on the company. It generally gives the candidate the chance to see some group interactions and some less formal social interaction rather than just seeing a one-on-one grilling from one technical interviewer. Often times, it's easier and less stressful for a candidate to ask a question to a group of peers over lunch rather than trying to fit all their questions in to the 10-minute window an interviewer allocates at the end of the hour.