Here's a Medium post that explains the slides, Verification 101: Storyful’s advice for checking out material from social media, and putting it into practice.
Storyful is a social media newswire, that uses journalistic techniques and standards to verify user-generated social media content.
First Draft News is a group of news media partners dedicated to helping reporters find and verify content that emerges online. Their site includes training guides for social media newsgathering and verification, like the video below.