Employers wanting to avoid the costly mistake of hiring the wrong candidate for an open position may resort to an in-depth interview. As opposed to a standardized interview, where each candidate is asked a set of more general questions, in-depth interviews require the interviewer to probe more deeply into the applicant's background to learn as much about him as possible. This in-depth approach does have potential drawbacks.

Interviewer Bias

In-depth interviews tend to be less standardized and rely more on the interviewer's own questioning style and choice of subject matter. As a result, the interviewer can intentionally or unintentionally introduce her personal biases into the process. Instead of uncovering character or personality traits that best suit the position or the organization, she may make judgments based on her own preconceived ideas of what the ideal candidate should be like. This may lead to eliminating candidates who may actually be an ideal fit.

Getting Too Personal

An in-depth interview can pose the risk of the interviewer venturing into areas that are inappropriate, or perhaps even illegal. Probing into a candidate's personal life can lead to questions about forbidden areas like sexual orientation, marital status, age or possible disabilities. While the interviewer may obtain important information about the applicant's background, he may also alienate a highly qualified candidate, or unwittingly pave the way for a lawsuit against the company.

Length

In-depth interviews often require more time due to the detailed nature of the questions and responses. If a company needs to fill a vacancy quickly, or wants to interview a large number of candidates, an in-depth interview can cause a lengthy delay in the hiring process. Qualified candidates who have other job prospects may decide to explore these opportunities if the hiring process drags on too long. Meanwhile, the company must adapt to the lack of production from an unfilled position.

Inconsistency

A standardized interview format ensures that each candidate is asked the same set of questions, making it easier to compare responses across the board. With an in-depth interview, the nature of the candidate's responses may lead the interview in a different direction for each candidate. Therefore, when it comes time to evaluate each candidate and make a hiring decision, the result can be an "apples to oranges" comparison, which can make the choice more difficult.