You
may need only the very latest information, or you may need information which was accurate as of a certain year or decade.
When evaluating a source, figure out:
When was this published?
Figure this out by:
looking for the date on the magazine's or journal's cover or on the first page of the article
reading the publication history of a book (on the back of the title page), checking if the material has been revised or merely reprinted since it was first published
searching the library catalogue to get the latest edition of a particular book or the latest publication on a particular topic
studying the citations in the author's text and bibliography to see how current his/her sources were
referring to the packaging or first screen of an electronic database to see what period of time its contents cover
checking the Web page or the site's homepage for the date the material was created and last updated (use your browser to find that date through the View or File menu).