Hmm...If I understood your proposal correctly, you were suggesting a useful framework to respond to the often difficult assessment of how to determine whether a licensee has created a derivative work. My response was that your proposal/suggestion that the abstraction-filtration-comparison (AFC) test be viewed as the appropo test was an intriguing suggestion. I then raised two primary concerns: [1] that what "modifications" constitute derivative works is the open source problem that licensors seem to struggle with and the AFC test is neither intended, nor useful for such matters and [2] at bottom, the AFC test is used by courts to determine what aspects, if any, of the allegedly infringing work constitute a copyrightable work that may have infringed the plaintiff's work. Although the circuits do not agree on how to apply this test, I doubt that one can find more than an isolated court opinion that has adopted the AFC test as a tool to determine the constituent elements of a derivative work. I agree that one principle underlying the AFC test - - that you "filter" out the non-literal (or, literal) element that is uncopyrightable - - is a helpful guideline in circumstances when a licensor is overreaching by claiming a licensee created a derivative work by copying/modifying/using a non-literal element from the original work. In such simple cases, a derivative work will not exist. I don't see examples of this type being typical open source issues, however. [snip] Sorry, Rod, but I'm going to have to disagree with you on this point. See Tradescape v. Shivram, 77 F.Supp.2d 408 (SDNY 1999). Comparing two works as whole against one another to see how "significant" the diffs are between them is absolutely not the test for derivative work in any Circuit. Although such an initial "first look" is sometimes performed, it is not determinative as it would too often lead a court to protect uncopyrightable portions of the original work. I think what you are addressing is whether the second author has significant originality to be deserving of her own copyright in the derivative work. See Torah Soft v. Drosnin, 136 F.Supp.2d 276 (SDNY 2001) ("All that is needed for a finding of sufficient originality is a distinguishable variation that is not merely trivial"). But, simply finding sufficient originality such that a second work deserves its own copyright doesn't impact the analysis of whether that second work is a derivative of the original. [snip] I am not sure that the point in your last paragraph about originality not impacting that analysis of a derivative work is correct or, at least, not without notable exception (e.g. whether a derivative work is created by the computer colorization of film seems inextricably tied to the originality question). Rod -- license-discuss archive is at http://crynwr.com/cgi-bin/ezmlm-cgi?3