A derivative work is a work based upon one or more preexisting works. Translations, musical arrangements, dramatizations, fictionalizations, are each examples of derivative works. In short, any other form in which an original work may be recast, transformed, or adapted can be considered a derivative work.. A work consisting of editorial revisions, annotations, elaborations, or other modifications, which, as a whole, represent an original work of authorship, is a "derivative work" (Source: Title 17 U.S.C. Section 101).
Scholars and researchers frequently find themselves working in the realm of derivatives. The nature of the academy presumes that new work will be solidly based in the seminal research that lays the foundation for advancing knowledge and understanding. The right to create derivative works is one of the exclusive rights of copyright owners and any assertion that the creation of a derivative work qualifies as a fair use would rely heavily on the transformative and productive nature of the purpose of the new work.
A thorough four-factor analysis is essential to an assertion of fair use regarding derivatives. And, naturally this is an area where ethical concerns for accurate and appropriate attribution also come into play as plagiarism issues arise along side copyright responsibilities.