No verbatim record of the proceedings is required. The claim file and written record, if any, produced at the highest agency level of review, including all written materials submitted by the Petitioner or Respondent and reviewed by the Public Agency, shall be forwarded to the Arbitrator by the Public Agency with or prior to filing of an answer and shall constitute the initial record before the Arbitrator. The Parties may submit and file in advance of the hearing any additional written, photographic or demonstrative evidence or may object to materials submitted by other Parties. In addition, summaries of anticipated testimony, declarations of witnesses and written arguments or briefs may also be required by the Arbitrator. Based upon the initial record and any additional evidence and written arguments submitted in advance of the hearing, the Arbitrator shall establish the issues to be tried.