Ask yourself some of these questions when you're evaluating different kinds of sources.

Accuracy

• Is there a bibliography or list of citations?
• Is the information based on verifiable facts?
• Do the facts agree with other reputable sources you have found?
• Did the source go through some kind of quality control process? (e.g. an editorial process; peer review)
• Are there spelling or grammar mistakes?  (This shows carelessness)

Authority

• Is there a specific author cited?
• Does he or she list work at an institution (such as a university or research institute) with a good reputation?
• What are his/her qualifications?  (PhD, research chair, etc)
• Is the site sponsored by an organization?

Bias

• Is the information presented based on fact or opinion?  Is there an obvious bias?
• Is the site sponsored by an organization?  Might that organization bias the facts presented on its website?
• Does the author appeal to emotion or to logic?

Audience level

• Is the source written for professionals or academics?
• Are the words used simple or technical?

Date

• Does the source list a date of publication?  How recently was the source written?
• What is the date for the data cited in the report?
• Have there been any significant changes in your topic since this source was written?