In this chapter, unless a different meaning plainly is required:
(1) “Official proceeding” means a proceeding heard, or which may be or is required to be heard, before any legislative, judicial, administrative, or other governmental agency or official authorized to take evidence under oath, including any referee, general or special magistrate, administrative law judge, hearing officer, hearing examiner, commissioner, notary, or other person taking testimony or a deposition in connection with any such proceeding.
(2) “Oath” includes affirmation or any other form of attestation required or authorized by law by which a person acknowledges that he or she is bound in conscience or law to testify truthfully in an official proceeding or other official matter.
(3) “Material matter” means any subject, regardless of its admissibility under the rules of evidence, which could affect the course or outcome of the proceeding. Whether a matter is material in a given factual situation is a question of law.