Hence, the test results can be dead wrong. No matter how good a test is, the predictions made based on one test are only as good as what that test measures and the predictive validity and reliability of that test. And, in my experience, those who do not understand test construction or validation, which represents the vast majority of those who use tests like the MBTI or DISC or Predictive Index and many others, go way beyond what is reasonable in their assertions regarding the accuracy of their predictions based on those test results. Does this mean that their predictions will always be wrong? Of course not; many of the descriptors that flow out of the test, if the person responded honestly, will apply. Unfortunately, while some people make every effort to respond honestly, subconsciously or even consciously, people often respond to test questions based on what they think the desired answer ought to be or how they want to be seen.
I’m not advocating to stop testing. The question is, “how do you increase the accuracy of predictions?” First, you need context about that person. Which includes conducting in-depth interviews of that individual. The research suggests that the interviews which have the highest reliability are behavior-based interviews. These are often structured interviews as opposed to free-wheeling and assess people based on dimensions associated with behaviors which are known to distinguish those who perform well in specific roles, organization cultures and specific work situations, from those who are less successful.
Once the assessor knows what those crucial behaviors, attributes, skills and abilities are, a battery of tests can then be assembled which specifically measure these. In most cases, these tests, in part, pose overlapping, albeit not identical, questions which tap into similar behaviors. Thus, if a person consistently shows a preference for one style over another, then there is a higher likelihood that given certain conditions and expectations, this person will function in a reasonably predictable manner.
Again, does this mean the results will be more accurate? The answer is “yes”. But, it is important to remember psychological tests are samples of behavior. So, the more samples you have, whether based on tests or interviews, or both, then the stronger the likelihood that what you are predicting or asserting about the individual is more accurate or on point.
It is very important to remember that the outcome of blood tests, scans, x-rays for purpose of diagnosis are crucial to how the patient is treated, so to we have all seen serious decisions made about people’s careers as a function of testing. Similarly, in the hands of a layman, physical test results can be easily misunderstood, so too can the results of psychological tests.
While it is kind of “party game” to take these quick and dirty tests, regardless of how long they have been around and how many people have completed them, it can be downright dangerous to apply these in settings where the consequences can be life changing.
Like I said at the outset, I haven’t seen the movie. But, I wonder if I’ve anticipated the moral of the story.