Not all studies are equal. A problem can be studied a number of different ways. One of the more interesting questions answered with research is finding the cause of some phenomenon. This is useful in Public Health, especially when it comes to controlling the spread of disease. This is most evident as, now in 2003, we are still dealing with the spread of infectious diseases, most notably SARS (Severe Acute Respiratory Syndrome).

Unfortunately, ethical research principles do not allow for “intentional exposure to disease” of humans just to see if what we suspected to be the cause of a disease is the actual cause.