According to the federal regulations, human subjects are living individuals about whom an investigator conducting research obtains information through interaction or intervention with the individual, and uses, studies, or analyzes the information; or:

a	Obtains, uses, studies, analyzes, or generates identifiable private information.
b	Obtains, uses, studies, analyzes, or generates de-identified private information.
c	Observes public behavior.
d	Obtains, uses, studies, analyzes, or generates identifiable public information.