Focus on interests, not positions (by Roger Fisher & William Ury)

Deze dingen komen veel te vaak voor. Spijtig genoeg is er dan ook meestal geen 'librarian'.

Consider the story of two men quarreling in a library. One wants the window open and the other wants it closed. They bicker back and forward about how much to leave it open: a crack, halfway, three quarters of the way. No solution satisfies them both.
Enter the librarian. She asks one why he wants the window open: “to get some fresh air.” After thinking a minute, she opens wide a window in the next room, bringing in fresh air without a draft.

This story is typical. Since the parties’ problem appears to be a conflict of positions, and since their goal is to agree on a position, they naturally tend to think and talk about positions - and in the process often reach an impasse.
The librarian could not have invented the solution she did if she had focused only on the two men’s stated positions of wanting the window open or closed. Instead she looked to their underlying interest of fresh air and no draft. This difference between positions and interests is crucial.