Reliability:
Timeliness

Check information sources to see if they are current or out-of-date for your topic. Topics of continuing and rapid development (e.g., scientific topics) demand more current information. Some ideas once believed to be true were later disproved by new discoveries. Fields such as medicine or law might require more time-sensitive information than fields like philosophy or history. For topics in areas such as the humanities or social sciences, older information may still be appropriate and valid.

Ask yourself the following: When was the information created, published or compiled? Is the information regularly updated and how often? Is the information still valid for your topic?

When was the information created, published or compiled? Most information sources indicate a date of publication. If a source provides no information on when it was created or published, it may not be appropriate to use if timeliness is important for your topic. Is the information regularly updated and how often? Certain information sources like the NationalDebt Clock on the Web are updated continuously or daily. Other information sources are updated at regular intervals, such as monthly or annually. Remember: The currency of a Web page can be important. Information that changes frequently, such as stock quotes and news events, should be found on pages that are updated regularly. Some sites may not be updated, such as personal pages or government reports, either because they contain information that doesn't change or due to poor site maintenance. Is the Information Still Valid? Some information remains valid over time for certain subject areas. The Bill of Rights (the first 10 amendments to the Constitution) is an example of a document which is still valid after 200 years. Fragment of the earliest known draft of the  Bill of Rights   Maps made between 1945 and 1990 show that Germany used to be two countries, East Germany and West Germany   Sometimes, information may become discredited or obsolete. For example, older maps may not reflect geopolitical changes that have occurred. In other cases, information may be periodically revised. First  Edition Second  Edition

Remember: When searching the library's online catalog for books, look at the publication date for each title that you find if you need more recent information.