(1) Subject to the provisions of ORS 36.450 to 36.558, the parties are free to agree on the procedure to be followed by the arbitral tribunal in conducting the proceedings.
(2) If the parties fail to agree, subject to the provisions of ORS 36.450 to 36.558, the arbitral tribunal may conduct the arbitration in such a manner as it considers appropriate.
(3) The power of the arbitral tribunal under subsection (2) of this section includes the power to determine the admissibility, relevance, materiality and weight of any evidence.