Content Summary : Personality tests are especially attractive to prospective employers because they measure charac- teristics that are not trainable. Hiring an employee with the wrong characteristics can be expensive to theorganization. Dissatisfied customers in a service-oriented business can quickly add-up to significant loss-es. Recruiting and training costs alone can burn up several thousand of dollars per employee. Personalitytests are powerful tools to ensure high performance, and prevent problems before they’re hired. The key isto pick good measures, and use them as a part of an overall hiring system tailored to the job. Personality traits cannot be accurately determined through interviews and cognitive ability tests. They need to be assessed using instruments designed specifically to measure the different aspects of per-sonality that are job-relevant. Developing a personality test is a tedious and lengthy process that requiresspecialized skills. Many items in a personality test seem like simple descriptions of daily activities. Becausethey seem superficially simple, some charlatans have created so-called personality tests that really don’twork. A scientifically developed instrument has items that have been carefully chosen based on a theory ofjob performance and tested across several hundreds, or even thousands of people. They are subjected tocomplex statistical analyses to select good questions that validly measure the traits of interest. Using scien-tifically-validated tests have been shown to payoff for many different types of companies.