Think of legal research as a way to get from here to there and to convince others to go with you. Even judges, perhaps especially judges, are uncomfortable going, in the words of Star Trek “where no man has gone before.” 
Legal research provides the stepping stones of authority showing that others have gone from here to there before and that “there” is the right place to go.
Here are some of the stepping stones:
- Direct authority—a clear and definitive statement in the applicable constitution or statute or by a controlling court or other body (use may require briefing to establish the body’s status as controlling when preemption, choice of law, and similar issues are presented; if there is no statute, then a regulation; if the highest court has not spoken, then an intermediate court).
- On-point authority that lacks precedential value—a decision of a court of equal or lesser status, a court of another state or the like (although not binding, this authority may be very persuasive; use is strengthened by citation to other courts that have followed the authority and to anything that supports its reasoning and result).
- Indirect authority—a variety of pronouncements of courts, legislatures or other official bodies that are relevant and tend to support the point indirectly. These include:
- existing construction of statutes that are similarly worded or in pari materia,
- rules of statutory construction that can be persuasively applied to support the point,
- analogy that may provide reasoning for or against a proposition.
- Secondary authority—a variety of statements by bodies or persons that are not courts, legislatures or other official bodies. These include:
- powerful sources such as the Restatement or a Uniform Law and its commentary (these reflect a consensus of judges, scholars and practitioners selected for their knowledge),
- legal and other treatises (their strength depends on quality, relevance, recognition by the same and other courts and other factors),
- law review articles (strength depends on the reputation of the author and the law review, relevance and timeliness, quality of the writing and other factors),
- state documents, such as reports by commissions and departments.
An attorney who has occasion to be in the chambers of a judge handling a pending case should take note of the books the judge has in chambers, especially the ones located close at hand to the judge’s desk. Insight into the sources a judge relies on regularly can inform research and citation of authorities to the benefit of that attorney’s clients.
Image courtesy of Flickr by Fimb (creative-commons license, no changes made).