Some studies will pay you for your participation. Before you agree to participate, you will be told whether you will be paid, how much you will be paid, how you will be paid (gift card, check, etc.), and when you will be paid (at each visit/session, at completion of study, etc.). Payment is not meant to convince you to participate, but to thank you for your time and to cover any costs you may have incurred by participating, such as for travel or taking time off work.