The board of arbitration shall hold hearings and shall have power to administer oaths and compel the attention of witnesses by subpoena and the furnishing by the parties of such information as may be necessary to a determination of the issue or issues in dispute. Both parties to the dispute shall have the opportunity to be present at the hearing, by representatives and by counsel, and to present such oral and documentary evidence as the board shall deem relevant to the issue or issues in controversy.