 |
Hypothesis-testing studies are either observational or experimental.
In observational studies the epidemiologist observes without
participating in the clinical process. In experimental studies,
the epidemiologist plays an active role (usually by proxy) in the
study. Observational studies have to be conducted when the
epidemiologist cannot ethically or practically intervene (i.e.,
he/she cannot give someone a cancer or a heart attack; he has to
wait for it to happen). Nor are people always willing to change
their behaviors at someone else’s request (i.e., start or stop
smoking or put on a lot of weight).
|
