Name, email and DOB are the obvious identifiers, but info such as age, race and zip code can also be identifiers in certain contexts.
Only ask for identifiable information that is necessary to your study
Avoid certain topics if you want your survey to be considered low-risk.
Sexual attitudes and behaviors, disclosure of legal activities, depression and other mental health disorders, violent crimes, and opinions about employers are just some examples of high-risk topics.
Consider your population.
If your study involves a population that might not be able to properly consent to research conducted online (e.g. children, people with cognitive disabilities, etc …), you might need to rethink the traditional consent model. Your study may not be low-risk.
