"The historians and students read vertically -- staying within the original website in question to evaluate its reliability." (Spector)
Vertical readers are often duped by unreliable indicators such as:
"The fact checkers read laterally -- quickly scanning the website in question but then opening a series of additional browser tabs, seeking context and perspective from other sites." (Spector)
Lateral readers exercise habits that lead to more thorough and efficient evaluation of information/sources such as:
Lateral reading: Instead of staying with one website or article, you might need to jump around a bit. Open multiple tabs in your browser to follow links found within the source and do supplemental searches on names, organizations or topics you find. These additional perspectives will help you to evaluate the original article and can end up saving you time.
Things to remember:
Wineburg, Sam and McGrew, Sarah. Lateral Reading: Reading Less and Learning More When Evaluating Digital Information (October 6, 2017). Stanford History Education Group Working Paper No. 2017-A1. Available at SSRN: https://ssrn.com/abstract=3048994