Not all ideas require attribution, specifically, facts that are common
knowledge. Common knowledge exists when a fact can be found in numerous
places or is likely to be known by a lot of people. For example, you do not
need to document the fact that Abraham
Lincoln was the 16th President of the United States since this
information is widely known. On the
other hand, you must credit your source for facts that are
not generally known or ideas that interpret facts. For example, Lincolnís tall and gangly stature is consistent with symptoms of Marfan
syndrome (Davidson, 2004).
Information from reference sources such as
encyclopedias, dictionaries, almanacs, etc. often does not need to be cited.
This is because the purpose of reference sources is usually to collect
together common knowledge on a subject. However, not citing reference
sources is at best a loose rule of thumb. Whether a reference source needs
to be cited depends more on the nature of the information than the type of
source. It also depends on the studentís reason for citing the information.
For example, if you wish to establish authority for the information, then
you need to cite the source:
Physicians consider abnormal elongation of the long bones to be a primary
characteristic of Marfanís syndrome (Merriam Webster). However, if you are merely
trying to inform your reader of something that is common knowledge in a
field, then it is not necessary to cite the source:
One of the main characteristics of Marfanís syndrome is abnormal elongation of the