Arbitration, in the context of the law of the United States, is a form of alternative dispute resolution. Specifically, arbitration is an alternative to litigation through which the parties to a dispute agree to submit their respective evidence and legal arguments to a neutral third party (the arbitrator(s) or arbiter(s)) for resolution. In practice arbitration is generally used as a substitute for litigation, particularly when the judicial process is perceived as too slow, expensive or biased. In some contexts, an arbitrator may be described as an umpire.