The catchall term "secondary sources" or "secondary authorities" encompasses a wide variety of publications. The characteristic all of these publications share is that they consist of descriptions of or commentary on the law, and not the law itself. The law upon which your analysis of a problem must ultimately rely is embodied in primary authorities (constitutions, statutes, case law and regulatory materials) which may be mandatory or persuasive depending upon the controlling jurisdiction. Secondary authorities can serve many purposes, but can never be mandatory or binding precedent. Keep in mind when using these sources that they must never be used as the essential underpinnings of your legal analysis or argument.
Nevertheless, secondary sources can be invaluable aids to the researcher. They may be profitably consulted at almost any stage of the research process.
Secondary sources can provide a springboard for beginning a research project. At this stage the researcher may consult secondary sources:
Secondary sources can also be valuable midway through or closer to the end of a research project, when consulting them can help to confirm conclusions or refine analysis.
Obviously, for any particular research project, you do not need to consult all the secondary sources available. This contrasts with the importance of comprehensiveness in primary authority research. Eventually you will develop preferences among the sources available, along with an instinctive sense for which sources might be helpful for a given project. Additionally, the resources available at the location where you are conducting your research will dictate some of your choices. The following are some guidelines for choosing a secondary source for a particular topic and for using secondary sources in general: