Ohio Revised Code Title XLI. Labor and Industry § 4123.10

The industrial commission shall not be bound by the usual common law or statutory rules of evidence or by any technical or formal rules of procedure, other than as provided in sections 4123.01 to 4123.94, inclusive, of the Revised Code, but may make an investigation in such manner as in its judgment is best calculated to ascertain the substantial rights of the parties and to carry out justly the spirit of such sections.