The last analytical type of epidemiologic study in presented on this slide.  It is called a prospective study and the goal is looking at the future outcome.  In other words, at present time we know an individual�s potential risk factors.  Therefore, the goal is to follow subjects who have been exposed and not been exposed to potential risk factors for a given period and observe the outcome of the disease.  This type of study is openly used in diabetes research.  DCCT and DPT is a few of the prospective diabetes research we have been hearing about for a long time.