Many interviewers need to use two of the best candidate selection techniques when hiring: validated assessments and structured interviews. Unfortunately, unstructured interviews are not much better than a coin toss when deciding who to hire. Companies hiring new talent would significantly improve their selection success and save costs using these two more reliable practices.
Let’s define terms
Structured Interviews. A structured interview is based on the knowledge, skills, abilities, and competencies to perform on the job and align with company values. With structured interviews, the company creates a set of questions to ask each candidate to determine if they have the education, experience, technical skills, social skills, and emotional intelligence to do well on the job. It is very focused on learning more information on the candidate’s role in previous jobs and uses the candidate’s resume or LinkedIn profile to ask questions. The premier researchers of candidate selection techniques, Hunter and Schmidt, found that structured interviews were the third-best selection method after work samples and aptitude tests.
Unstructured interviews have no or minimal fixed set of questions to be answered, or specified procedure for scoring applicant answers. In many cases, different job candidates will be asked different questions. (This practice alone can get you into legal trouble if your hiring discriminates against protected classes.) Research shows that unstructured interviews have very little predictive value, meaning it is really a matter of luck whether you are making the correct hire.
Making matters worse, the research often shows that during unstructured interviews, many interviewers make a hiring decision in the first five minutes based on the way the candidate looks, the university they attended, or if they know friends of the interviewer. Typically, the interviewer then spends the rest of the interview looking for evidence to confirm their decision. When empirical researchers, such as Hunter and Schmidt, look at the validity of unstructured interviews, they find it scores no more than .38. (In empirical research, job candidate selection validity means the test or interviewing technique is successful in hiring good candidates. The closer to “1,” the better the selection test or process.)
Assessment Tests. Assessment tests can take the form of intelligence tests, or tests to determine who will make a good manager, executive, salesperson, assembler, or data scientist. All assessment tests should be validated to make sure they hire candidates who will do well on the job and do not discriminate against protected classes. There are many aptitude assessments on the market. Before selecting one, ask for evidence that it has been validated and does not have a bias against protected classes. In addition, these tests hold up well in court, based on the research of Shoenfelt and Pedigo.
Let’s look at the evidence
Empirical studies conducted in the 1980s and 1990s have shown the strength of general cognitive ability and aptitudes tests and structured interviews over unstructured ones. Aptitude tests lead the way after work sampling (which I will explain below). Structured interviews have higher reliability and predictability than unstructured ones. A more recent meta-analysis on structured interviewing, conducted in 2014, arrived at the same conclusion as the earlier studies. The 2014 study says: “Twelve meta-analyses have been conducted on this topic, and they have consistently found strong evidence for the superiority of structured interviews compared to unstructured interviews.”
Schmidt and Hunter’s 1988 meta-analysis found that structured interviews were the third-best selection method, with a validity factor of .51. It rises to .63 when used with a General Mental Aptitude Test. (GMATs are tests that measure various aptitudes depending on the job, such as logical reasoning and are very predictive when validated. Validation means that they have been statistically proven to predict great performing hires.)
Below is a chart of Schmidt and Hunter’s research that shows 18 interviewing methods. On the left are the best methods. On the right the worse methods. Please note work sampling (having the individual do a representative sample of the actual work) is the best method, but most companies find this is too time-consuming outside of hiring manufacturing workers. GMAT (General Mental Aptitude Tests) , now commonly known as assessment tests is number 2, followed by structured interviews. The green diamond represents Emotional Intelligence testing which wasn’t measured by Schmidt and Hunter but has been shown since their landmark research to be highly predictive when hiring managers, salespeople, and others who deal with the public. I highly recommend using emotional intelligence tests or questioning when hiring with these fields. Unstructured interviewing is the orange column in the middle of the chart.
The worse selection methods are on the right of the chart, which include:
- hiring by age
- handwriting (which once was a craze)
- the interest in the job
- years of experience (research shows that after about two years, experience is not valid on a job because the skills needed change),
- the point method (when job candidates are awarded points for specific training and experiences. It is often used in civil service).
The research by Schmidt and Hunter shows that when two of the top methods are used in selection, GMAT (which is aptitude testing) and structured interviews, tremendously raises the reliability of great hires. Aptitude testing and structured interviews raises the reliability of great hires to .63 validity. (The only other more reliable method is integrity testing—examining whether the candidate is honest and reliable–mixed with other aptitude test). The chart below shows the blue columns you saw in the previous chart alongside orange lines, representing the combined strength of aptitude tests with each selection method.
Previous research has also shown that structured interviews work well with video interviewing allowing managers to engage with the interviewer by seeing facial expressions and making eye contact. And research shows that structured interviews hold up well when challenged in court.
You can learn how to set up structured interviews here.
Organizations and their recruiters can significantly improve their hiring success and save costs by using general aptitude tests and structured interviews over unstructured interviews or other unreliable factors such as job experience after two years, and age.
About Victor
Victor Assad is the CEO of Victor Assad Strategic Human Resources Consulting and Managing Partner of InnovationOne, LLC. He works with organizations to transform HR and recruiting, implement remote work, and develop extraordinary leaders, teams, and innovation cultures. He is the author of the highly acclaimed book, Hack Recruiting: The Best of Empirical Research, Method and Process, and Digitization. He is quoted in business journals such as The Wall Street Journal, Workforce Management, and CEO Magazine. Victor has partnered with The Conference Board on innovation research. Subscribe to his weekly blogs at http://www.VictorHRConsultant.com
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