Okla. Stat. tit. 19 § 901.30-4
The arbitration board, acting through its chairperson, shall call a hearing to be held within ten (10) days after the date of the appointment of the chairperson and shall, acting through its chairperson, give at least seven (7) days of notice in writing to each of the other two arbitrators, the bargaining agent and the corporate authorities of the time and place of such hearing. At least seven (7) days before the date of the hearing the bargaining agent and the corporate authorities shall submit to each other and to the arbitration board members a written arbitration statement listing all contract terms which the parties have resolved and all contract issues which are unresolved. Each arbitration statement shall also include a final offer on each unresolved issue. The terms and offers contained in the arbitration statements shall be known collectively as each parties' last best offer. The hearing shall be informal and the rules of evidence prevailing in judicial proceedings shall not be binding. Any documentary evidence and other data deemed relevant by the arbitrators may be received into evidence. The arbitrators shall have the power to administer oaths and to require by subpoena the attendance and testimony of witnesses, the production of books, records, and other evidence relative or pertinent to the issues presented to them for determination. A hearing shall be concluded within twenty (20) days from the time of commencement. Within seven (7) days after the conclusion of the hearing, a majority of the arbitration board members shall select one of the two last best offers as the contract of the parties. The criteria to be used by the board in determining which offer to select shall be limited to those in Section 6 of this act. The arbitration board may not modify, add to or delete from the last best offer of either party. Written notice of the selection decision shall be mailed or delivered to the employer and the union.
Okla. Stat. tit. 19, § 901.30-4