A booking can only be rated when it has actually taken place. Instructors can also not delete ratings. Furthermore, it is only possible to create, edit or delete a rating for 14 days after the end of a booking. This ensures that ratings are created shortly after a booking and can not be changed for whatever reason, long after the booking has taken place. So generally speaking, ratings can be considered to be trustworthy and real.
We also do our best to spot and delete fake or misleading ratings, and take any appropriate actions against those abusing the rating system.