Scott Smith, vice president of HR at High Country Millwork and Fleetwood Fixtures, providers of custom retail spaces, furnishings, and fixtures, started using online personality assessments seven years ago to help him make hiring decisions. He thinks they reveal things that his human interviewers frequently miss. "Oftentimes," says Smith, "someone interviews very well, and then we run the assessments and find red flags that were not readily apparent," such as a tendency to get aggressive under pressure.

This information, along with follow-up interviews, has "prevented us from hiring candidates that we may have hired without the insights of the assessment," Smith adds. "They help us refine our final interview questions and pick the right person."

Large companies have used personality tests for decades, usually under the guidance of expensive psychologists. But Web-based employee screening and selection assessments, which cost about $400 or less per test, are an increasingly popular option for more companies. Ira S. Wolfe, president of Success Performance Solutions, a consulting firm that specializes in Web-based personality tests for small businesses, says his company set revenue records each of the past three years, growing 15 percent in 2014 alone. Caliper, a test maker, reports that usage of its products has climbed nearly 160 percent in the past five years.

Other popular test brands include Profiles International, Hogan Assessment Systems, Assess Systems, and PeopleClues, but plenty of psychologists have created their own blends. In general, these tests ask candidates to agree or disagree with a series of statements intended to gauge hard-to-measure areas such as assertiveness and dependability. The programs use data analyses of the answers to determine when a candidate might shine or struggle in a particular job.

Such tests also help companies scale their hiring. "We want to systematize the hiring process," says Chris Presswood, co-owner of Murray, Kentucky-based Finish Line Car Wash & Detail. The family-owned company, which began using PeopleClues employment tests at the end of 2013, fields about 1,000 applications a year and asks candidates to take the 30-minute online test. Presswood thinks seeing the results helps less experienced hiring managers quickly learn what to look for in a candidate. "We don't want to just hire on a hunch or a good feeling," he says.

Some of the best-known personality tests, such as the Myers-Briggs, aren't usually recommended for screening purposes, says Gary Kaufman, a test developer and owner of Human Resources Consulting. Those offer a description of a candidate's personality, but don't compare it with a job profile, as hiring programs do.

When companies avoid using online assessments, it's often because they aren't closely enough aligned with the job being filled. "In my experience, it's hard to have an objective test that captures everything you need in a job," says Jody Miller, co-founder and CEO of Business Talent Group, a company that provides independent consultants for project work. She prefers to create detailed job descriptions and ask candidates questions related to the job tasks.

The assessments have other potential drawbacks. The Equal Employment Opportunity Commission is investigating whether some discriminate against people with psychological disabilities like depression. Wolfe says these tests are generally legal as long as they don't try to uncover disorders, are job-related, and are used consistently. "They can tell you if someone is more excitable than the next person, but not if they have a mental illness."

Finding the Best Test

Putting a hiring test into practice is hard work. "I probably looked at 15 or 20 tests before we chose one," says Ellen Wisniewski, HR administrator at Parmenter Realty, a commercial real estate firm headquartered in Miami. It was worth the effort. "There are a lot of people selling snake oil out there," cautions Robert Hogan, founder of Hogan Assessment Systems and a test developer since 1967.

Keep the following points in mind when choosing a job-candidate personality test.

  • Make sure it's easy to use. Will the test be easy for candidates to take, and will managers be able to easily interpret results? If not, be prepared to lose potentially good hires. You'll probably also see poor usage rates by hiring managers.
  • Be exact with benchmarks. An ideal test will compare your candidates' responses against standards of behavior for a certain job title. Since the test's job description typically isn't customized to your company, make sure the job used for comparison on the assessment closely matches the position you're filling.
  • Ask for credentials. "The test publisher should be able to give you references from peer-reviewed journals as to how well it works," says Gary Kaufman of Human Resources Consulting. If not, beware. "Anyone can put one on the internet and claim it works," he says.