Remember when evaluating a website to use for this assignment that many conditions may have a association/foundation site (Parkinson's Foundation or The Michael J. Fox Foundation) or a College/Medical site (Perelman's Parkinson's Disease and Movement Disorders Center) that you could use instead of commercial sites. There are options out there--think why am I choosing this site over others (authority, credibility, date last updated, etc.)? And/or what does this source tell me what others might not?