What they mean to say is…What teachers and librarians usually mean is don't use Wikipedia as a cited source in your paper. Because it can be edited by anyone, there is a good chance it contains incorrect or biased information. It is probably okay to use as a starting point to get an overview of your topic, but don't stop there. For a more detailed explanation of why you shouldn't rely on or cite Wikipedia in your project, check The Top Reasons Students Cannot Cite or Rely on Wikipedia on the Finding Dulcinea website.
But Wikipedia is still a great research tool…
Wikipedia, as well as other general encyclopedias from the LRC, should not be your only source in a paper. Unless your teacher tells you otherwise, use an encyclopedia only as a starting point for your research.
1. Get an overview of your topic. Use an encyclopedia article to get basic information about your research topic. Reading a short general article will allow you get the basic facts and generate a list of subtopics you will need to research. Wikipedia excels at topics that are too current to have made it into a library encyclopedia—up to date information about pop culture, technology current events, etc. A Wikipedia article for a national event might be created and totally up to date within the hour of it happening.
2. Look for keywords It is important to generate a list of words that you can use search terms in search engines, LRC databases or the indexes of books. As you skim the article for your topic, look for names, events, places and other topics related to your topic. These will help you expand your research, especially if you get stuck. More detailed information here.
3. Use the references and external links sections. Wikipedia and other encyclopedias articles are relatively short summaries of information form books, magazines, websites, etc. These articles are intended to be a survey or overview of information about the topic. If you are using Wikipedia or an LRC encyclopedia, make sure to check out to articles references section. This is the equivalent of the Works Cited lists or Bibliographies your teachers have probably had you create for your projects. Also check out the external links (in Wikipedia) or suggested sources (or similar category in other sources). Both areas point you to more detailed in-depth information about your topic. Plus, you can cite most of these sources in your paper).
4. Look out for flagged articles. Since Wikipedia articles can be edited by pretty much anyone anywhere in the world, there are sometimes problems with articles: incorrect information, biased points of view, a lack of citations for information, etc.
Example of a Flagged Article Section: