In the research process not everything you find on your topic will be suitable.  It is important to critically evaluate the resources you discover to ensure that you are using the most appropriate materials. Timeliness, relevance, author and audience, and point of view/bias are important factors that should determine whether or not you decide to use a source for your topic.
 

The T.R.A.A.P method is a guide to help you evaluate how credible and useful the sources you find will be in answering your research question, supporting your points, convincing an audience, etc.

When you look at a source (a chapter of a book, an journal article, a blog entry, etc.), ask yourself the following questions:

Timeliness

• How current is the source? When was it created and/or published?
• Does your topic or subject area require up-to-date information (i.e. medical and science fields, current events, etc.)?
• Is the date your source was created likely to affect the content or the author's conclusions?

Relevance

• How closely related is this source to your research question? 
• What is the purpose of your research and will this source further that purpose?

Author & Audience

• Who is the author? 
• What are the author's credentials? 
• Is the author associated with an organization, agency, profession, or movement?
• Sometimes information about the author is listed somewhere in the article.
• Who is the intended audience of the source? The general public? Other academics? A specific group?
• Is the material too technical or too clinical? Is it too elementary or basic?
• Who is YOUR intended audience for the product of your research? How might your audience view this source?

Point of view/bias

• Does the source convey a particular opinion or position? 
• Is the source attempting to persuade someone or sell something?
• Is the source part of a larger publication? If so, what is it and what is the mission or purpose of that publication?
• Are the author's sources clearly cited? If so, what kinds of sources did they cite?

Another factor is the type of publication, Scholarly vs. Popular. Scholarly resources are written by experts for experts. These sources are peer reviewed, have extensive bibliographies, and often contain areas for further research.

Use Google Scholar to find background information on authors and researchers.