When trying to determine the authority of an author, consider these questions:
Keep in mind what each domain represents:
.com = US commercial website
.edu = US educational website affiliated with a university
.gov = US government website
.org = Organization or non-profit site
Keep in mind the intent of the website. Is it trying to teach, persuade, or sell you something?
To determine the authority of an author, click on the author's name or look for their information at the bottom of the article. There you can find background information on the author as well as other articles the author has written.
Sometimes you may need to look up additional information about the author or website to determine its credibility. It can be tricky sometimes.