The usual way we look for signs of Authority and Purpose is by poking around the website and letting the creator tell us about themselves, their organization, what the intentions are of the website and more. We look at what type of website it is because we have learned that a .org will be more reputable than a .net site. We look to see if there is a way to contact the organization. We look up and down the pages for ‘About Us’, ‘Who We Are’, ‘Our Philosophy’. We feel satisfied if there is an author bio.
But this limits us to what the organization and content creators want us to know about them - the story they want to share. Consider this - if a website wanted to appeal to a broader audience and ensure that the info on their site is used, might they showcase themselves in a specially-crafted way?
Lateral reading allows you to quickly and efficiently get to the truth by taking a quick scan of the site but then jump off of the site and look at what others are saying about organizations and individuals.