It is assumed that everything in a paper that you hand in under your own name is entirely your creative work. You are the author.
When some portion of a paper is not entirely of your own creation, it is your obligation and duty to inform the reader of this fact. The easiest situation (1) is where a portion of text has been taken as a whole from the work of some other person. In this case, you simply enclose the text in quotes and give a suitable reference to the source. In a somewhat less well defined situation (2) you have lifted an idea from another author but the textual version is your own. This is called paraphrasing and you are duty-bound to make suitable reference to the source of the idea if that source can be considered unique and, hence, if the idea is not in some sense common knowledge. A more abstract situation than this (3) is when you present material in your own words but the material is not drawn from your own experience or direct research and observations. Hence, you should periodically refer the reader to where reports of this material can be found. Failing to give proper references in any of these situations represents plagiarism.
Needless to say, submission of a paper that has been wholly written for you by someone else represents the highest order of seriousness and is the most extreme offense.
References
You may gather materials for a research paper from different sources. Here are some examples.
Interviews and personal observations --- you may do original research. If this is the case, you should treat the situation just as you have been taught in laboratory courses. Keep a notebook or make audio/video tapes. Date items and include lists of people and places.
Books, journals, newspapers, magazines, or archived records --- give enough information so that a reader can easily return to the original source to verify the material. This includes authorship, titles of articles, journals, anthologies, books, etc. You should include publication details. For unique archived sources you should include the place where these materials are located.
Internet sources --- the WWW is coming to be used increasingly as a source of information and that is acceptable. HOWEVER, you must give (1) complete URL references AND you must include (2) a thorough summary of authorship and institutional sponsorship/basis for the Web site. If these are not available the Internet material may not be included. (If, for example, the Web site is presented by an individual, you must be able to document who the individual is and what qualifications he/she possesses in order to present this material.) Also, since unlike books Internet materials change periodically, you should date your use of a particular site. (E.g., URL such-and-such on this-or-that date.) [A Special Warning: The Internet has made it extremely easy to appropriate texts electronically. Please be very careful in handling Internet materials and give thorough credit when credit is due.]
Common reference formats are illustrated in the writing handbook used in Hum 1 each year. Please conform to one of these.