I tend to believe that starting with a well defined goal is an undeniable prerequisite for publishing a quality paper on a certain topic.
Alas, can a PhD revolve around a fuzzy subject, that offers the student a lot of freedom of choice regarding what problem to solve, as long as the problem is solved using the methods in that field of study?
More explicitly, is it possible to develop a quality research paper in an applied scientific field without fixing the goal beforehand?