Informal job interviews lead to bias in hiring: study

By Suelan Toye

Have you ever been asked in a job interview what kind of sports you play? Most interviewers tend to ask questions unrelated to the job they’re recruiting for, which may lead to biases in selecting the most qualified candidate, a U of T researcher says.

“With structured interviews, you ask the same set of job-related questions to each candidate so you can make a fair comparison between them,” says Professor David Zweig, a specialist in organizational behaviour at U of T at Scarborough’s Department of Management and co-author of a study published in the September issue of the journal Personnel Psychology.

“With unstructured interviews, you have a lot of biases creeping in. If they like you, they’ll throw these soft-ball questions at you and try to find ways to support their initial impression. Structured interviews have also been shown to have up to eight times the predictive power of pinpointing the best candidate compared to unstructured interviews.”

Zweig and lead author Derek Chapman of the University of Calgary asked 592 interviewers from over 500 Canadian and international organizations to fill out a questionnaire examining the level of structure during the interview, their reaction to the interview and the amount and type of formal interview training they had received. The interviewers were hiring students from a large Canadian university for a four-month work term. The researchers also asked 518 applicants to complete two questionnaires – one before and the other after the interview – which probed their reaction to the interview and their intention of accepting the job if offered to them.

They also found only one-third of interviewers had formal training, and this group favoured more structure during the interview process. “That’s way too low. Everyone should receive formal training on how to conduct a structured interview,” Zweig says.


David Zweig, U of T at Scarborough Department of Management, 416-287-5613; e-mail: