Well-Defined Problems

One trouble with much of programming is simply that often there is not a well-defined job to be done; rather, the programming process itself will gradually discover what the problem is! The desire that you be given a well-defined problem before you start programming often does not match reality, and hence a lot of the current proposals to “solve the programming problem” will fall to the ground if adopted rigorously.

The Art of Doing Science and Engineering, by Richard W. Hamming