Why is email address required on the screening form?

We require email address on the screening form for multiple reasons:

1. It helps us prevent bots and scammers.
   1. We use email address as the unique identifier to prevent multiple screening form entries from a single person. 
2. Having multiple contact methods for each lead increases response rates. Additionally, if a potential participant makes a mistake when filling out their phone number, email can serve as a backup contact method (or vice versa).