Interviewers may all share the same goal -- hiring the right person for the right job -- but they may get there in different ways. Some use structured interviewing techniques, following a set format in all their interviews; others take an unstructured approach, allowing interviews to create their own format. While both techniques can be successful, they come with advantages and disadvantages.
How Structured Interviews Work
Structured interviews follow a rigid format set by the interviewer. Before you start interviewing, you create questions specific to the job and your hiring requirements. These are often either behavioral questions that ask candidates to describe how they have handled past situations or situational questions that ask how they would handle hypothetical scenarios.
Typically with a structured interview, you ask the same questions of every candidate in exactly the same order, giving each the same time to respond. You record the candidate's responses and score each answer at the end of the interview.
How Unstructured Interviews Work
Unstructured interviews are more informal with a free-flow conversational format. You may start the process with a set of core questions, but you won't necessarily ask them all or keep to any order. You may also ask questions that are more open-ended and take more time to answer, enabling you to learn more about the candidate as a person. Every interview in the process may be slightly different, as each candidate's responses will shape the questions you ask and the direction the interview takes.
Advantages and Disadvantages of Structured Interviews
Structured interviews evaluate all candidates objectively and equally. This gives an "apples to apples" comparison with the benefit of a scoring system that identifies the best candidate. According to the U.S. Office of Personnel Management, this standardized structure may also protect you against legal challenges from disgruntled candidates who don't get the job.
However, structured interviews may lack spontaneity. You can't chat with candidates or ask off-the-cuff questions that might reveal more about their personalities and competencies. This kind of interview can be quite cold and clinical, making it harder to build rapport with candidates.
Advantages and Disadvantages of Unstructured Interviews
Unstructured interviews give you a more subjective view of candidates, allowing you to focus on their personalities as well as their competencies. You can choose the direction that interviews take, using more detailed and tangential questions to get a more rounded view of candidates and their strengths and weaknesses.
However, this technique may make it more difficult to evaluate candidates. If interviews don't have a common structure, you may have to make more of an "apples to oranges" than like-for-like comparison. This lack of structure may also introduce bias into the decision-making process and you may subconsciously hire candidates you relate to rather than those with the best competencies.