First, what is the echo chamber effect? You need to use the link above to know what echo chamber effect means and explain it in your own language.

Second, how may (1) biases in information seeking, (2) framing by news media with different credibility and political ideology, and (3) the way information spreads through social networks lead to the echo chamber effect?

Please pick two out of the three potential factors and explain their potential relationship with the echo chamber effect in your own language.