The following information about “confirmation bias” is presented here in three forms. Just below, there is a link that goes to an eleven page summary in PDF form, edited from a much longer Wikipedia page on the subject.
Following that link, there are three PowerPoint slides which further shorten and summarize this complex and fascinating phenomenon.
Finally there are two links, the first which goes to more complete information on confirmation bias on Wikipedia, and the second which goes to pages on the broader subject of cognitive biases, also posted at Wikipedia.
I suggest first reading the three Powerpoint slides below. If you want more detailed information, open the eleven page summary PDF at the following link: