No matter where you may have retrieved information from, it is important to have a critical approach to your sources. Remember that information found on the Internet can be published by basically anyone, so you might have to pay extra attention to the critical evaluation of those sources.
To evaluate your sources consider the following questions:
• ACCURACY & COVERAGE - WHAT does the material contain?
Reliability: To which extent is the information credible and accurate? To evaluate the reliability, your own experience and knowledge as well as the source's reputation plays an important role. Does the source have fact checkers or editors?
Relevance: How relevant and/or useful is the material for your needs? Which topics are covered, and to what depth?
References: Which other sources has been cited in the work/material?
Scholarly: Is it a scholarly text or popular science?
Target audience: Who is the intended audience (scholars, school children, general public, et.c.)?
• AUTHORITY - WHO is communicating the information?
Author: Is the author well known in their field of research? Does the author have academic legitimacy? Has he/she been published before? Is there any way to contact the author? In short - what are the author's qualifications for writing on the subject?
Publisher: Who is responsible for the information - a company, an agency, an organization or an individual? Any contact information? Serious publishers often clearly express who they are and what they do. How reputable is the publisher?
• OBJECTIVITY - WHY was the material published?
Purpose: What is the purpose of the material/document? Inform, present research, disseminate views, entertain, sway the opinion of the audience...? Is the information presented with a minimum of bias?
• CURRENCY - WHEN was the material produced/written?
Up to date: When was the text written? Is the material enough for you topically? Is the publication/web page dated? Updated? If the date is included it may have various meanings: date first created, date placed on the web or date last revised.