Credibility

Credibility indicates whether the author and publisher seem reliable.

Is the author listed? For some sites - like government and corporate sites - the organization might be the author.

What do you know about the writer? Is there an "about" page? Does the writer have credentials that give you confidence that he or she is an expert?

Is the publisher reputable? (On the web, publisher means which organization hosts the web page. This is often difficult or impossible to tell. More on that in a moment.)

If you can't find any information about the author or the organization, be suspicious.

While the credentials are important, it doesn't mean a source is correct. It's one indication that it is more likely to be reliable. For "serious" topics, credentials are usually an important factor.