Judges engaged in statutory interpretation can also call upon a range of external aids and information, called extrinsic materials. These extrinsic materials include, but are not limited to:
Precedent. Naturally, the judge will also consider precedents when interpreting legislation. Previous judges may have ruled on statutory meanings, intent or interpretation; if this occurred in a higher court in the same jurisdiction then it will be binding upon inferior courts. If it occurred in another jurisdiction then the judge may choose to follow it as a persuasive precedent.
Dictionaries. Both plain English and specialised legal dictionaries can be used to assist decisions about the specific meanings of words in the Act.
Parliamentary debates. Judges can refer to Hansard and review the arguments and statements made by parliamentarians when the legislation was being debated, usually during the Second Reading or committee stages. By referring to these debates, judges can better understand the motives, purposes and intentions of parliament when it passed the legislation.
Reports. If the law has come about from a recommendation by a law reform body or parliamentary committee, the judge may examine their report. The judge may also consider other government reports, such as white papers. Again, the purpose of this is to obtain a fuller understanding of why the legislation was created, its purposes and intentions.
Interpretation legislation. All Australian legal jurisdictions have active legislation that guides and determines how other legislation should be interpreted. Examples include the Interpretation of Legislation Act (Vic, 1984) and the Acts Interpretation Act (Cth, 1981). The purpose of these is to ensure that legislation is interpreted fairly and consistently throughout the jurisdiction.
Documents. If the intrinsic materials refer to any documents or data, the judge may choose to examine these. They may provide context for the legislation or more information what it was intended to address, achieve or correct.