We recently compared KeyCite to Shepard's online as part of a Lawyering Skills exercise. We found that both services listed the same cases and most of the same law review and journal articles as citing references for cases. Although they both list treatises, they only list the treatises owned by their respective companies – Shepard's lists LexisNexis treatises and KeyCite lists West treatises.
KeyCite lists court documents, which Shepard's does not. Although briefs and other court documents may be helpful as examples for writing assignments, and they may cite to primary and secondary authorities relevant to your research, their usefulness is otherwise very limited. Documents filed by parties to litigation are not primary authority (the law itself), and they are rarely persuasive outside the case in which they were filed. Furthermore, unlike treatises, journal articles, ALR annotations and other secondary authorities we covered this semester, court documents have not been subjected to independent editorial review. It is up to the researcher to determine whether the documents are current, accurate and reliable.
Shepard's includes statutes in its Citing References. No, of course, statutes do not cite to cases, so a statute cannot literally be a citing reference. Shepard's lists a LexisNexis annotated statute as a citing reference for cases that have cited the statute and are listed in its annotations. Here's an example. If you Shepardize Totz v. Continental Du Page Acura, 236 Ill. App. 3d 891, 602 N.E.2d 1374 (1992), one of the citing references will be 815 ILCS 505/2, the current version of a section of the Illinois Consumer Fraud and Deceptive Business Practices Act, to which Totz cited.
You may be wondering about the value of the inclusion in a Shepard's report of annotated statutes to which a case has cited. Would it not be easier for a researcher to find the statutory citation in the case and go directly to the statute? In most cases, probably yes. However, Totz is a good example of how the Shepard's listing can be helpful. Totz did not cite to 815 ILCS 505/2, but to its predecessor, Ill. Rev. Stat. 1989, ch. 121 1/2, par. 262. Although there are translation tables in print that would allow a researcher to convert Ill. Rev. Stat. citations to ILCS citations, on LexisNexis the Shepard's report appears to be the most direct link from Totz to the statute.
Although KeyCite does not include annotated statutes in its citing reference lists, citations to previous versions of statutes in cases on Westlaw are linked to the current versions of the statutes, even when the statutes have been renumbered.