It is a negative rational number. Whether it is for evaluate or anything else makes no difference.
evaluate the evidence used to support it
Sometimes you may be asked to evaluate your supervisor. When you do so, consider things such as how well your supervisor communicates and whether or not you feel that your supervisor is fair.
is it necessary to have periodically assess and evaluate policies because it determines whether the policies are still current & relevant to your organisation & to its clients. Whether the policies suits their intended purpose or whether they need to be changed, eliminated, replaced or even updated.
It depends on whether or not they get paid
no, it is the participants own choice whether or not they want to become a professional athlete. Most of the time a professional athlete cannot participate in the olympics.
check their color
It helps if you know a bit about the corresponding scientific area.