There are many articles out there that provide advice about how to conduct job interviews.
They can sometimes be valuable, but most are based upon the experiences and opinions of just one person. How do you know if they are relevant to you, or even accurate?
Fortunately, researchers have been objectively studying job interviews for nearly a century, providing a wealth of information on what tends to work best.
Here are 7 useful tips based on science.
1. Prepare for the interview by conducting a “job analysis”
Before the interview even begins, it is important to do your homework.
Interviewers should consult with at least one “Subject Matter Expert” to generate a specific list of the most important aspects of the job, and what is required to perform successfully. Subject matter experts can be anyone with the right knowledge and experience, including hiring managers, supervisors, and current experienced employees.
Sticking to the subject matter on this list during interviews has several notable benefits: The information obtained from candidates is relevant to the job, more such useful information is obtained, and less content that is irrelevant to the job is discussed (a prepared interviewer is less likely to “wing it” and ask irrelevant questions). Furthermore, interviews based on job analysis are viewed more positively by both job candidates and interviewers, and tend to be less biased against legally protected categories.
2. Prepare interview questions in advance
For many of the same reasons that it is good to prepare by conducting a job analysis, it is also good to prepare the specific questions that you will ask candidates.
An interview format in which all candidates are asked the same specific questions further ensures that information obtained from candidates is relevant and comprehensive, and that irrelevant content is avoided. When all candidates are asked the same questions, their responses are more directly comparable—this increases the validity of the interviews, and mitigates potential biases.
There are three basic types of question format that have proven the most useful (and are preferred by most interviewers surveyed, relative to other types of question).
- Behavioral Interview Questions: Ask candidates about previous experiences in which they were able to demonstrate the basic competencies that are relevant to the job. This method is based upon previous experiences that may or may not directly resemble specific situations encountered on the job, but it allows the candidate to demonstrate basic competencies, thought processes, and behaviors that are directly relevant.
- Situational Interview Questions: Ask candidates what they would do in a specific hypothetical situation that they are likely to encounter on the job. While this method calls for speculation, it allows the candidate to demonstrate their basic competencies, thought processes, and likely behaviors, even if their previous experience is not directly relevant to specific situations encountered on the job.
- Background Questions: Ask candidates to describe their relevant experience, qualifications, or training.
3. Prepare for some degree of flexibility
An interview prepared following the above advice runs the risk of being too structured.
What if you ask a question and don’t get enough information from a candidate’s response? Interviews that simply move on to the next question at this point without room for follow-up questions often do not collect enough information from candidates. Furthermore, this format is perceived more negatively by both job candidates and interviewers.
You can maintain a basic structure by preparing specific follow-up questions to use whenever they are needed. While it is still somewhat important to ask the same follow-up questions of each candidate when necessary, the primary purpose is simply communicating to the candidate that they need to be more specific how and why something happened, provide examples, or describe in more detail their reactions to a situation.
4. Ensure that the interview is not too short, and not too long
An interview that is too short runs the risk of not collecting enough relevant information from candidates, or collecting inconsistent amounts of information from different candidates. An interview that is too long places too much burden on interviewers and candidates (and tends to be perceived more negatively by both parties as a result). An overly long interview process can also fatigue interviewers or potentially cause “information overload,” rendering interview evaluations less valid.
Most interviews are between 30 minutes and 1 hour, and contain at most 20 questions. Because it is important that all candidates are given the same opportunity to answer the same questions (and without feeling rushed) it is generally best to limit the number of interview questions. A general rule of thumb is to ask no more than between 4 and 6 questions in a 30-minute interview; and no more than between 8 and 12 questions in a 1-hour interview.
5. Focus on the interview during the interview
Information about candidates that is collected during the application process (such as resumes, test scores, or letters of recommendation) can differ widely between candidates and may become outside sources of bias and contamination during the interview process. If you can safely assume that candidates made it to the interview stage because they have the basic qualifications for the job, it is best to avoid referencing such materials in preparation for the interview or during the interview.
Despite what some experts recommend, the available evidence suggests that soliciting candidates to ask questions of the interviewer introduces contamination and bias, and reduces the reliability of evaluations made by interviewers. It is generally best to focus on the relevant interview questions that are asked of all candidates.
While avoiding these sources of bias and contamination is beneficial, an insulated interview process runs the risk of being negatively viewed as stiff, formal, and impersonal. To avoid this potential problem, it may be helpful to ask a candidate to describe their relevant experience, qualifications, and training, as an opening interview question. This gives the candidate the opportunity to provide more personal and specific descriptions, and often avoids the inclusion of irrelevant information. Furthermore, candidates can be solicited to ask questions after the conclusion of the interview, allowing engagement on a more personal level without concern that any such interaction will bias the previous interview content.
6. Include more than one interviewer
Sometimes the old adage “Two heads are better than one” is very true.
Including at least two interviewers provides the opportunity to determine if more than one person can reliably agree on the outcomes of a given interview process. The use of multiple interviewers itself increases the reliability of interview outcomes, such that different interviewers in a separate, subsequent interview are more likely to agree with the initial evaluations of the same candidate.
Multiple interviewers help keep one another on-task, resulting in interviews that obtain more relevant information and less irrelevant information from candidates, which in turn tends to increase validity and mitigate potential biases.
7. Take detailed notes during the interview
Interviewers who are instructed to take notes generally react positively to the experience, and find that doing so helps them to do their job better.
Give it a try for yourself!
There are a number of great reasons to take notes.
- Note-taking creates a professional atmosphere for the interview, and allows a candidate to feel respected, listened to, and encouraged—while minimizing the necessary amount of eye contact and other body language that can bias interview outcomes.
- Human memory is limited. We tend to remember the beginning and end of things much better than everything in between, and can more easily recall emotional content (such as if something was surprising or made us laugh). The things that interviewers remember later, without notes as a memory aid, are not necessarily the most important or relevant aspects of the interview. The problem of remembering who said what can be further compounded when larger volumes of candidates are interviewed.
- Having a set of specific notes for each interview allows you to make decisions based on all the information available, and to be specific about why you made those decisions. The decision to hire someone simply based on liking, a “good feeling” about them, or a sense that they were a “good fit” is not valid (or legally defensible). A solid decision based on specific competencies, behaviors, skills, or experience is much more so.