Bellwether trials include a smaller subset from a large group of plaintiffs. The legal issues of those in this subset are a good representation of the group. Sometimes there are multiple bellwethers for more extensive cases, like the 3M Earplug Lawsuit. The first trials serve as a benchmark and establish a precedent. Bellwether trials are sample cases in large mass tort litigation involving thousands of plaintiffs.When thousands of individual plaintiffs have similar claims, it 's impossible to take every case to trial. So instead, a small number of test cases are used to give those involved in the lawsuit a clear picture of the settlement compensation payments that victims should get.