“Personality testing is for the lazy.” That’s what I told someone recently when she asked my opinion of using personality tests for hiring purposes. To be fair about it, my statement was a little extreme – but it got her attention. Then we discussed the good and bad reasons for using personality tests in business. I’d like to share that discussion with you today.

Personality tests have their uses and their disciples. No doubt you have taken more than one in your career. One very popular test is the Myers-Briggs Type Indicator (known as the MBTI), which was developed by Isabel Briggs Myers and based primarily on the work of psychologist Carl Jung.

Some people argue that personality tests do not provide a very good measure of personality because they rely on people to be objective about themselves. A good test will have enough variety in its questions to overcome this problem.

In fact, most of the tests I have seen in use are good. They do what they claim to do, which is to give a personality profile of the person taking the test. The problem is not in the tests but in how they are being used.

When I said that these tests are for the lazy, I meant that some people use them as a substitute for exercising personal judgment. I can see three problems with relying on standardized tests to make hiring decisions.

1. Using a standardized test to make hiring decisions reduces the accountability of the decision maker. It becomes too easy to blame a bad hiring decision on the personality test. “I don’t know how he did it; usually people who score that well on the test do very well here.” Hiring is far too important for this.

2. Standardized tests are most effective when used in very large numbers. Only if you hire many dozens of people each year (and then systematically measure the validity of the test usage in your organization) can you be sure that the test is telling you what you need to know about your job applicants.

3. Standardized tests always leave some questions unanswered because no test can possibly test for the precise combinations of personality traits that you need in each of the different positions in your organization. Only you can do that.

Only you can be the best possible judge of a job applicant’s fit for the job. Only you can prevent poor hires. Here’s a step-by-step process to help you find the best fit from a pool of applicants.

1. Make a list of all the personality traits that are needed to do the job well. Some jobs require a high degree of empathy (sales, customer service). Others call for a lot of perseverance or independence (technicians, diagnosticians). Only you know what traits are best for the jobs in your organization.

2. Write out two or three behavioral interviewing questions for each of these traits. The idea behind this type of interview question is to get the candidate to tell you how he applied a certain personality trait on the job. Here’s an example of a behavioral interview question: “Tell me about a time when you had to keep going without giving up in order to get something done right or to solve a tough problem.”

3. Do this for every position in your organization.

4. Write these questions down and use them in every interview you do. Pay attention to the answers you get. All other factors being equal, the best candidates will be the ones who have used the right traits successfully on the job.

If you want the best people working for you, the only way to get them is to know what it takes to be the best person for the job. If you follow this system you will know what you are looking for in job applicants and you will know how to find it.