What is interest-based negotiation?

Collaborative Practice and Mediation are interest based processes. Interest based negotiation is a problem solving approach to conflict that focuses on needs, desires, concerns and fears rather than positions. 

A position is what we want (or think we want). An interest is the why beneath the position. For example, a position might be ‘I want a tuna sandwich.’ The why beneath that is that ‘I am hungry and want a healthy food choice.’ 

Positional bargaining or negotiating tends to lead to win-lose or zero-sum outcomes, where one person wins and gets what they want and the other person loses and doesn’t get what they want. Positional bargaining can also lead to compromises where one person gets half of what he wants and the other person gets half of what she wants.

Interest based negotiating often leads to win-win outcomes where each person gets their needs and desires met or their concerns and fears addressed. For example, if one person wants the window open and the other person doesn’t, a positional negotiation might lead to the window being open or closed or perhaps open halfway. An interest based negotiation might go as follows:
Why do you want the window open? Because it is stuffy in here and I want some fresh air.
Why do you want the window closed? Because I am fighting a cold and don’t want the draft.
A win-win solution might be to open a window in an adjacent room to allow some fresh air without creating a draft.

Another example is if two people both want an orange. A positional negotiation might lead to one getting the orange and the other not getting it or it might lead to the orange being cut in half. An interest based negotiation might look as follows:
Why do you want the orange? I am hungry and thirsty and the orange will satisfy both.
Why do you want the orange? I am baking muffins and I need the orange rind.
A win-win solution would be that one person gets the orange rind and the other person gets to eat the orange.

​If we don’t spend the timing asking for the ‘why’s’ beneath the positions, we miss opportunities to create win-win outcomes. 
A family law based example is:
Wife: “I want to keep the house.”
Why?
Wife: “Because it is near to the kids’ school.”
So it is important to you that the children are able to continue to go to the same school?
Wife: “Yes.”
So the interest is that the children go to the same school and one possible solution or outcome is that she keeps the house. There are other possible options that would allow the children to go to the school and depending on some of the husband’s interests, these options would also be explored in a collaborative negotiation or mediation.