Locate the fact on which both parties would change their minds, and argue about that rather than about the conclusion.
The procedure asks each side what would change their view, and looks for an item that appears on both lists. Where one exists, the disagreement has a testable centre and the discussion can be about it. Where none exists, the parties have learned something more useful than any further exchange would have produced: they are not disagreeing about the same thing.
In practice
- Two managers arguing about a hire find the crux is whether the role is permanent, which neither had raised.
- A pair who can name nothing that would change their minds have discovered the shape of the disagreement.