Researchers need the skills to explore all sides of their research topic. Young researchers often search exclusively for material that confirms their pre-existing notions of their topic. This creates results knows as confirmation bias.
Even experienced researchers can fall prey to this bias.
Try using comparison searching as a tool to helps your students become aware of comparison bias. Comparison searching enables students to develop more thoughtful and nuanced understandings of their research topics and the way they themselves ask questions and search for information. The process asks students to actively consider and evaluate two or more disparate results sets.
Glean Comparison Search uses this technique to help students explore different sides of a topic. The teacher guides provide a series of lessons that help students can come to understand and move beyond their own confirmation biases.
via Glean Comparison Search: An Educational Research and Search Tool. I was made aware of this page when reading: Free technology for teachers.