The Effectiveness of Using Mediation in Selected Civil Law Disputes: A Meta-Analysis

Executive Summary

Mediation is the process where an impartial party with no decision-making power intervenes between contending parties for the purpose of assisting them to reconcile, narrow, or settle a legal dispute. Proponents have identified mediation as a less adversarial alternative to court that can reduce costs, improve fairness and satisfaction.

Meta-analytic techniques are a quantitative method for aggregating knowledge, which have been used extensively in fields such as education and medicine, only more recently being adopted within the social sciences (Lipsey and Wilson 1993). Essentially, a meta-analysis aggregates the magnitude of a relationship between specific variables for collections of studies (Glass, McGaw & Smith, 1981).

Similar to many standard quantitative research methods, the meta-analytic process has three basic steps: literature review, data collection, and data analysis.Through an extensive literature review, and after contacting 85 individuals or organizations with expertise and experience evaluating mediation programs, over 250 sources were identified.

A specific set of criteria was then applied to ascertain if a study could be included in the meta-analysis:

  1. the study evaluated a mediation program concerned with tort or contract cases (not criminal law, Aboriginal law or family law cases);
  2. the study evaluated a use of mediation whose style was either evaluative, facilitative or transformative ('arbitration' and 'negotiation' were not included);
  3. the study used a control or comparison group that did not use mediation or used mediation of a different type;
  4. sufficient statistical information was reported in order to calculate an effect size; and,
  5. at least one of the following four outcomes was reported for both the mediation group and comparison group -
    • plaintiff satisfaction;
    • defendant satisfaction;
    • procedural fairness; and/or,
    • cost effectiveness.
  6. the study was conducted since 1980.

After applying the selection criteria, only 26 publications remained. Of these publications, some examined multiple mediation programs, while others examined multiple sites. In all, a total of 37 unique programs or sites were available for analysis.

Only 28 of the 37 unique studies of a specific mediation program at a particular site provided data that allowed us to generate the meta-analytic statistical measures called 'effect size estimates' (ESE), while 34 of the 37 unique studies provided data that provided us with averages for additional outcome measures. In all, 59 effect sizes and 97 other outcome measures were calculated. Operational data was augmented by surveys in most studies we evaluated. Thus, in addition to operational data this meta-analysis summarizes the responses of nearly 8,000 individuals' comments upon their experience with a mediation program and over 2,000 individuals who commented upon their experience with a comparison group process.

For 10 of the 17 outcome measures that we could analyse, mediation programs demonstrated a positive impact. Therefore, the meta-analysis does indicate some broad improvement in outcomes when there is a mediation program. In the following areas mediation is demonstrated to provide an improvement:

  • Measured Staff Hours Saved
  • Measured Case Length
  • Perception of Time Savings
  • Proportion of Cases Successfully Settled
  • Perceptions of Fairness
  • Satisfaction with the Outcome
  • Satisfaction with the Process
  • Perception of Compliance
  • Perceptions of Cost Savings
  • Measured Costs Saved

In many cases we could not make statistically confident statements about outcome measures. This may be due to the level of variability in what the studies found or the sample may have been too small to provide a clear picture. It might also be that the impact of mediation to that outcome measure is actually very low, negligible or could even be marginally negative. This was the case with seven outcome measures:

  • Measured Time Saved
  • Number of Hearings
  • Pre-Trial Conferences
  • Number of Motions
  • Long-term Satisfaction
  • Perceptions of Reasonable Cost

Six programs or sites asked respondents in the comparison group if they would have preferred to use mediation over the process they did use. Of the people surveyed by the studies, slightly less than half (48%) thought they would have preferred to use the mediation alternative.

We also examined 'moderator' variables, which are those variables that influence the strength of a relationship between two other variables (Henriques 1999) to try to ascertain the characteristics most associated or disassociated with a particular outcome. In most cases the analysis of moderator variables was not fruitful. The majority of moderator variables which could be confidently noted as improving an outcome measure could not be compared with any statistical reliability to any other moderator variable within the same outcome measure.

While these stand alone moderator variables may be strongly associated with effective mediation programs, they may also be artefacts of sample size. Thus, not many conclusions can be drawn from them. There were limited instances where more than one moderator variable within an outcome measure could be compared. However, in the majority of these instances either the confidence interval ranges of the moderator variables overlapped (indicating a similar impact) or one of the moderator variables was a catch-all category where one cannot be sure what was included. In only three instances, moderator variables could be more clearly compared with one another. The voluntary selection of mediation could reduce staff hours more greatly than mandatory mediation, case lengths are lower and measured cost savings are higher in mediation programs that are compared against comparison groups that only allow mediation ineligible case versus those that do. However, very small samples make drawing any conclusions from these comparisons difficult.

Only one moderator for one outcome measure in the meta-analysis found a negative outcome of mediation. In this one instance, the meta-analysis found that that programs where there was freedom to select to mediator resulted in a lower settlement rate than the comparison group, but that mediation programs where there was no freedom to select the mediator demonstrated an improved settlement rate.

Although the sample was too small to differentiate between types of mediation programs, the overall summary of the reported findings of mediation programs demonstrates definite positive benefits to using mediation.

Overall, mediation processes are fairly effective in creating both time savings and costs savings and that mediation results in improvements of at least 16% or 17% to perceptions of time and cost savings, which is also supported by documented savings in the areas of time and cost. Depending on the characteristics of the mediation program, these improvements could be up to at least 40%, but is more likely in the range of around 30%.

In addition, the meta-analysis shows that mediation results in improvements of at least between 3% and 6% to perceptions of fairness and satisfaction. Thus, mediation processes clearly result in marginal, but definite, improvements in perceptions of fairness and satisfaction. Depending on the characteristics of the mediation program, these improvements could be into the 15% to 25% range, but are more likely to be in the range of 10% to 15%.

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