There are two types of bias that are important to keep in mind during the research and writing process:
Confirmation Bias:
This is when you deliberately shape evidence to support your argument/agenda, and ignore information that supports the contrary.
For example: You are writing a paper that argues that vegetarians are better athletes because they avoid red meat. There is information that supports your argument, but there is also a lot of information that supports the opposing argument. Without acknowledging that this other information exists, your work has a confirmation bias.
Implicit Bias:
Implicit bias occurs when someone consciously rejects stereotypes and supports anti-discrimination efforts but also holds negative associations in his/her mind unconsciously. In other words, the work may say one thing, but express another by reinforcing stereotypes and prejudices that otherwise would suggest a prejudicial bias on the behalf of the author. It's important to be able to discern the intentions of the author of any piece of information that you absorb.