How do you identify its center and radius?

The  knowledge gap  as been recast more recently as a “digital divide”  gap. with the internet and social media many things can be done faster and better. so much faster and better that those that do not have access to them are literally left out of the game. 

Which element of a health-related website would suggest that the site may not be credible or reliable?

hyperlinks to other fitness, nutrition, or medical sites
tips for achieving instant positive results or an instant cure
details about a recent study on a medical issue or condition
safety warnings related to the information that is presented