Assessment tools often give candidates three or four possible answers to a question and force them to choose the one that characterizes them the most and the least. The problem is that the actual difference between the two choices may be different for different people.
Even in this case it is often impossible to understand the answers clearly. For example, the respondents can be asked whether they like talking to people. If they answer yes, does that mean they like to talk to everybody? If the answer is no, do they hate talking to everybody? What if they like to talk only with people they already know or those who approach them first?
People are so different that it is difficult to classify them into categories. Assessment tools should involve as many specific categories as possible.
Some tools only assess personality traits and do not reflect the ways people think. How a person behaves can be quite different. However, if you do not know how he or she thinks, you can hardly understand their behavior.
What kinds of personality tests do you have experience with? What tools work and which don't?
-kk-