The procedure by which a board or a single arbitrator, acting under the authority of both parties to a dispute, hears both sides of the controversy and issues an award, usually accompanied by a written decision, which is ordinarily binding on both parties. Arbitrators are usually appointed by the parties concerned, but under special circumstances, they ore appointed by the Minister of Labour. Compulsory arbitration is that required by law and is the usual procedure for settling contract interpretation disputes. The term voluntary arbitration indicates that the parties to a dispute agree to arbitration in the absence of statutory compulsion.