A study of 1,381 labor and family mediations was conducted in the Netherlands. Mediators completed questionnaires immediately after mediation. The questionnaires focused on the use of caucus before and during mediation, and on three outcomes at the end of mediation: whether agreement was reached, whether interpersonal conflict was reduced, and whether goal compatibility between the parties was increased.

The study found that pre-mediation caucusing was used more often for labor mediations. When goal conflict in labor mediation was greater, the mediators were more likely to use pre-mediation caucuses. In family mediation, the mediators were less likely to use such caucuses when the interpersonal conflict was higher. Nonetheless, pre-mediation caucusing was shown to increase likelihood of settlement and reduce post-mediation interpersonal conflict. It did not have an impact on post-mediation goal conflict.

Pre-mediation caucuses were most successful when they focused on trustbuilding because doing so reduced interpersonal conflict. On the other hand, using caucuses to push parties to accept a settlement proposal led to increased post-mediation conflict and had no impact on settlement.