Requests for review shall be filed in writing with the board stating the reason for which the award is sought to be modified or set aside. The board in its discretion may set a date on which the request may be considered and will give notice of the hearing to all parties. As soon as possible after the hearing is held, the board will affirm, set aside, or modify the award on the basis of the information available to it at the time from any source. The board may on its own motion correct typographical errors at any time (1974).