Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 58A, § 8

A hearing shall be granted if any party to an appeal so requests, and upon motion of any party to an appeal, or by direction of the board, any appeal may be set down for a hearing. Hearings may be held before less than a majority of the members of the board and the chairman may assign members to hold hearings. Hearings before the board, or any member thereof, shall be open to the public and such hearings and all proceedings shall be conducted in accordance with such rules of practice and procedure as the board may make and promulgate; provided, however, that such rules and amendments thereto shall comply with the filing provisions of section 5 of chapter 30A and such rules and amendments shall not take effect until so filed. The chairman may direct that two or more petitions for abatement of the taxes assessed upon real estate situated in the same general locality of the same town be heard together, irrespective of the identity of the appellants.