'Facts are different from ideas: facts may not need to be cited, whereas ideas must always be cited.' - Academic Integrity at Princeton University
When to Cite
Quotation- Any verbatim use of a source, even one word, must be placed in quotation marks and cited.
Paraphrase-Paraphrase is a restatement of another person’s thoughts or ideas in your own words. Don't use quotation marks but do cite the source you are paraphrasing.
Summary- is a concise statement of another person’s thoughts or ideas in your own words. A summary is normally shorter than the original.
Facts, Information, and Data- Often you’ll want to use facts or information to support your own argument. If the information is found exclusively in a particular source, you must clearly acknowledge that source.
When NOT to Cite
Common Knowledge-When facts or information is generally well known and accepted you do not need to cite a source.
Common knowledge does not require citation, but finding the same fact or piece of information in multiple sources doesn’t necessarily mean that it counts as common knowledge.
When in doubt- Cite.
Information taken from "When to Cite Sources." - Academic Integrity at Princeton University. N.p., n.d. Web. 24 Apr. 2013.