Q: I would like to self-publish a book-length criticism. Would my use of other sources fall under the terms of "Fair Use"?

A: As you probably know, the fair use doctrine is not a black and white formula and its application involves a number of considerations. In general, though, it is an available defense against an infringement claim in works of criticism, as you have described your work.

A court will look at four factors in analyzing whether the use is 'fair use': (1) the purpose and character of the use; (2) the nature of the work copyrighted; (3) the amount and substantiality of the portion used; and (4) the effect of the use upon the potential market. In addition, courts are interested in whether the use is 'transformative' of the original use, i.e., does the use create something new, or does it merely recycle the original work.

For each factor, you should consider the following: (1) the purpose and character of the use - has the original material been transformed by adding new expression or meaning to it? Is there additional value added by new information, insights, analysis, etc.? (2) nature of the work copyrighted - there is greater leeway in copying factual works, as opposed to fictional works. (3) amount and substantiality of the portion used - the less used, the more likely it's fair use. (4) effect of the use upon the potential market - will your use of the material deprive the original author of income or undermine a new or potential market for the original work? A court would then weigh and balance your work against the 4 elements, and often the financial element receives the most weight. Use of an acknowledgement of the original source material will not avoid a claim of infringement, but it may be considered evidence of fair use.