Tenenbaum and Raffman (2012) claim that "most of our projects and ends are vague." (p.99) But I'm not convinced that any plausibly are. On my own blog, I recently discussed the self-torturer case, and how our interest in avoiding pain is not vague but merely graded. I think similar things can be said of other putative "vague" projects.
T&R's central example of a vague project is writing a book:
Suppose you are writing a book. The success of your project is vague along many dimensions. What counts as a sufficiently good book is vague, what counts as an acceptable length of time to complete it is vague, and so on. (p.99)