Factor Two: The Nature of the Copyrighted
Work
This factor generally weighs in favor of fair use
if the work to be used is factual in nature (scholarly, technical,
scientific) rather than works involving more creative expression
such as plays, poems, fictional works, photographs, paintings and
such. The case for fair use becomes even stronger when there are only
a few ways to express the ideas or facts contained in a factual work.
The line between unprotected "facts and ideas," on the one hand, and
protected "expression" on the other, is often difficult to draw. If
there is only one way or very few ways to express a fact or an idea,
the expression is said to have merged into the fact/idea, and there
is no copyright protection for the expression.