When first speaking with customers, we try to establish realistic goals and expectations for a pre-employment testing program. So what kind of results should you expect from using pre-employment tests? By using professionally developed, validated testing instruments you are adding objective, data-driven metrics to your hiring process. Using tests should drive incremental improvements in your hiring results, and minimize the risk of bad hires. It should also dramatically streamline your hiring process, and translate into demonstrable improvements in your business by reducing turnover, lowering hiring and training costs, and improving productivity.
OK, but it's just as important to be realistic and realize what you should not expect from pre-employment testing. Tests are not a crystal ball, unfortunately. Anyone who tells you otherwise is lying. When you see testing companies say things like, "Never make a bad hire again" or advertise 99.9% accuracy, it means they are either ignorant of how the science behind testing works, or misrepresenting it to sell you their tests either way run, don't walk, in the opposite direction. Incorporating tests into your hiring process does not mean you'll never make another bad hire, only that you will make fewer of them. No test is a perfect predictor. Some people who don't test well may be great employees, and some that test well may be terrible employees. Research shows that tests are significantly more accurate and reliable as predictors than resumes or interviews, but there is no selection methodology that will be 100% accurate in predicting performance.
That's why we always recommend that tests should be only one element of a comprehensive set of criteria you use to evaluate applicants. Sure, you can use tests at the top of the process to screen out candidates who aren't a good fit, but ultimately, organizations that use tests are making their final decisions based on many factors, of which tests should be an important component. A good way to look at is this no matter how well developed a test is, you should not try to outsource your hiring decisions to a testing company. Tests will help you make better talent decisions, but they are not the only factor in those decisions. You should expect tests to streamline and improve your hiring process, not replace it.