How can you determine a source's biases? Why is it important to consider a source's biases?

Check these sites.

http://asher813.typepad.com/dreams_into_lightning/2006/05/how_can_you_det.html

http://answers.yahoo.com/question/index?qid=20060814110837AA20E70

Those with bias are likely to not mention all factors related to the topic being discussed. Rather, they only mention those points that support their bias or contradict other views. Listening to communications with a certain bias leads you to make decisions without having adequate information.

I hope this helps a little more. Thanks for asking.