When a company offers additional compensation based on the contingency of certain goals being met by individual employees, this is referred to as?

Gyou are in charge of making the work schedule for the next two weeks. typically this is not a difficult task as you work at a routine 8am – 5pm company. however, over the next two weeks you are required to schedule someone to be in the office each saturday. after contemplating this for a few days you make the schedule and assignments. before posting the schedule for everyone you decide that it is a good idea to meet personally with the two people you have scheduled to work the weekend. what do you say to them? what is your desired outcome?