The test of the model also incorporates an estimate of the impact of a change in the statutory impasse procedures governing these groups. The model examines the impact of (1) alternative sources of impasse, (2) situational characteristics, (3) strategies of the mediators, and (4) personal characteristics of the mediators on the probability of settlement, percentage of issues resolved in mediation, movement or compromising behavior, and the tendency to hold back concessions in mediation. The results indicate that the change in the impasse procedure had a marginal affect on the probability of settlement in the small to medium cities in the sample but little or no effect on the larger cities. Furthermore, a number of other measures of the sources of impasse and mediator strategies and characteristics had a stronger impact on the effectiveness of the mediation process than the nature of the impasse procedure. The study instrument is appended and 31 references are listed. (Author abstract modified)