The validity and reliability of opinions lie in their underlying methodology and evidence base. Reliance on the personal authority of any expert or group of experts is the fallacy of appeal to authority.
I have asthma but that does not make me a Pulmonologist. That addiction “specialist” diagnosing and treating you may have 5 years prior been a proctologist; and maybe not even a very good one at that.
Somewhere there may be doctor with no post-graduate training in surgery wielding a scalpel and calling himself an expert surgeon, but it is difficult to imagine that he is a very good one.
“How to Position Yourself as an EXPERT, Make More Money and Help More People, by Becoming a Published Author – Even if You Don’t Know Where to Start!” Think about it – if you need to see a chiropractor, for example, would you rather see a general chiropractor, or one who has positioned …
http://leighstjohn.com/free-educational-webinar-how-to-position-yourself-as-an-expert/
Disrupted Physician 