People are always looking for “the best” personality assessment tool, and in doing so, it is important to first do two things:
1. Develop a basic understanding of the science of human behavior
2. Develop a basic understanding of Psychometric instruments (personality assessment tools)
With a clear understanding of the above two things, there are many tools available that will help you.
It is important to understand that all of these tools are only as good as the person using them, so if you’re administering the assessment, you must educate yourself. The first thing I always suggest starting with is an understanding of the difference between a Trait and Behavior.
Your Personality Traits originate from within the synaptic connections between your neurons, or brain cells. They are formed about a month of two before we are born and are the basis for our recurring patterns of thought and feeling, which predict our behaviors. Further development continues, but by the time you are fifteen years old, your core personality Traits are formed.
Behaviors are predominately learned and are primarily manifested by our Traits. After the age of fifteen, we spend the rest of our lives learning how to behave in different situations. That being said, it is important to understand that in times of stress and anxiety – you know, a typical day at work—people will always revert back to the behaviors manifested by their hardwired natural traits.
When determining if a person has the right behaviors for a job, you need to compare their Personality Traits against the required behaviors of the job. Examples of Traits include, attention to detail, assertiveness, willingness to be accommodating, being methodical, sociability, etc.
With a basic understanding of Psychometric instruments (personality assessment tools), you will then realize that you need a tool that measures both traits and the person's perception of behavior, to what degree that these are "hardwired" for that person and what their innate ability is to sustain changed behavior. With this knowledge, you will then find that there are only a handful of tools on the market that clearly and quickly provide that information.
Remember that this is a science. However, it is not an exact science, so the fact that one tool "claims" that it is a little more accurate than another is predominantly based on marketing! So whatever tool you decide to use, make sure that the publishers of the tool have conducted the proper validity testing and that they make that data available to the public.