One key part of evaluating a source is to look at the person or persons who wrote it.  The author’s credentials can show if the author is a specialist, or has done research on the subject.  Obviously a medical text written by someone who is not a doctor would be suspect—just as a book on economics written by a chemist might be suspect.  Specifically, you should try to answer the following questions about the author.

• Is the author’s education related to this subject?
  
  

• Is this author well known in the field?
  
  

• What else has this author written on this subject?
  
  

• Have other experts critically examined the writings of this author?  (If so are they favorable about the item you are looking at?)