Power
The ability to coerce someone to do something he or she would not otherwise do
Rights
independent standards of perceived legitimacy or fairness
Interests
Needs, desires, concerns
Rights based approach
Who is right and who is wrong? Who has the legal right in this dispute? Who is likely to win in court? Who has the moral high ground? What is a third-party likely to decide?
Power based approach
Can either party force the other to accept a deal?
Who has a stronger BATNA?
Who is in a position of authority?
Who can afford a protracted legal battle?
Who can make the other’s life miserable?
Interest based approach
What are each side’s underlying interests?
What are each side’s concerns?
Are there mutually profitable alternatives to litigation?
Is there a way to satisfy each party’s interests?
Getting back to interest from P and R