What is important to identify before reading and analyzing a source for research?

When evaluating a source, you first need to know whether it would be considered as a potentially reliable source, meaning, what type of publication is it? If it is an internet Blog post by an unknown writer, that would have less reliability than a book written by a top expert in the field. Generally speaking, a book published from a top publisher (SAGE, for example) ranks highest. An established professional journal ranks high as well. Then come general readership magazines. Then newspaper articles. Internet sources always rank lowest--unless you use an .edu website with writings from professors or others with credentials.

As far as determining author bias, you often cannot decide the bias without first reading the article/work. However, if the Title or Publisher has a known or easily identifiable bias, you might know the "slant" before reading and analyzing a work. For example, if the article was published in a journal paid by the Klu Klux Klan, you can suppose part of the bias. In a magazine titled Sharks, written about sharks, you likely won't find articles about killing them--so the "bias" might be conservation. But if you find an article about sharks in a magazine called, High Powered Sport Reeling, you'd know it likely talks about catching sharks with some hook and reel fishing method-- the bias: that hunting and fishing is glorified as a sport.

So always try to determine if the publication itself would be ranked high. Then look for clues about bias. But you may not know author bias without first skimming or reading the article.