Information may have a particular bias towards an ideological, political or commercial viewpoint. A critical analysis of a source as well as of the author’s background is needed to identify evidence of bias. Bias may be the result of a selective representation, but also of selective omission. Clearly opinionated sources should be identified as such and counterbalanced by opposite or alternative viewpoints. The inclusion of various main viewpoints will, when done properly, result in a comprehensive treatment of the topic.
Websites offer ‘About Us’, ‘Colophon’, ‘Contact and/or Copyright menu items from which you can distill more information about an organization’s mission. URLs usually indicate broad categories of organizations (.gov for government, .edu for educational, .org for non-profit and .com for commercial organizations).
An area for concern are ‘fallacies’ (including sweeping generalizations). The Writing Center at UNC-Chapel Hill provides more details in the handout Fallacies (PDF).
‘Technical’ research may include social assumptions as for instance research on cancer treatment seems to result in higher success rates for men and lower rates for women, due to the recruitment of male test subjects. In a similar way, pharmacological dosage for children seems to be less reliable due to the recruitment of adult test subjects. The assumption being that children are small adults rather than assuming a different metabolism.
When treating a topic for which only a limited number of sources are available, the risk of bias should be reduced by looking for alternative sources, if need be non-academic. In general, peer reviewed publications are preferable when looking for objective sources.