When trying to spot bias, ask yourself these questions:
1. What kind of information is it?
News? Opinion? Ad? Does it appeal to your emotions or does it make you think?
2. Who and what are the sources cited and why should you believe them?
Is the source given? Is the source associated with a political party or special interest group?
3. What’s the evidence and how was it vetted?
What’s the evidence and how was it vetted? Is the source a document? Witness? Or is it hearsay/speculation?
4: Is the main point of the piece proven by the evidence?
Did the sources provided justify the conclusion or main point of the story?
5. What’s missing?
Was there an aspect or point that was not covered or unclear that you are left wondering about?
Based on American Press Institute.
A study (PDF) on media bias from University of Chicago economists Matthew Gentzkow and Jesse Shapiro, used text as data to look at common Democratic and Republic phrases in Congress. You can consider these phrases when you are tyring to determine if a source or politician is conservative of liberal.