The board shall establish, and may from time to time modify and amend, rules and regulations for:
(1) The conduct and determination of benefit cases appealed to it, or to an appeal tribunal;
(2) The form of all papers and records thereof;
(3) The time, place, and manner of hearings;
(4) Determining the rights of the parties; and the rules need not conform to the common-law or statutory rules of evidence and procedure and may provide for the determination of questions of fact according to the predominance of the evidence.