Ten Mistakes Even Good Mediators Make

1. Failing to get the right people at the table.

2. Failing to explain the mediator's role as "agent of reality."

3. Permitting settlement negotiations to begin prematurely - prior to permitting the parties to vent or prior to risk analysis and reality testing.

4. Failing to orchestrate the negotiations by discouraging "out of the ballpark" offers or demands or by discouraging moves that send the wrong signal.

5. Failing to recognize that unrealistic expectations must be lowered gradually.

6. Being evaluative (a) too early or (b) in a joint session.

7. Failing to suggest ways to avoid reactive devaluation of sensible settlement proposals for the adversary.

8. Believing "bottom line" offers or demands (see also Michael Wheeler's Is that really your best offer?)

9. Failing to "test the waters" before making a mediator's proposal.

10. Being impatient or failing to be persistent or giving up prematurely

[Thanks to Stephen A. Hochman for the list - the links are mine]