When trying to decide whether or not you can trust information found online - no matter what type of information it is - always ask yourself:
These are the same questions used by professional fact checkers. Watch the video below, which is part of the Crash Course series titled Navigating Digital Information, to find out how they do it.
When you see a claim that may not be 100% true, there are four steps, called "moves," you can take to fact-check the claim. If you successfully confirm a fact at any stage, you can stop - it's not always necessary to complete all four moves.
In addition to the fact-checking moves, you should get into the habit of checking your emotions. When you feel strong emotion – happiness, anger, pride, vindication – in response to a claim, STOP. Above all, these are the claims that you must fact-check.
As human beings, our emotions tend to override our ability to reason. It's important to learn to recognize when this is happening, so you can approach important issues with a more analytical frame of mind.