The Use of Online Databases for Legal Scholarship

By Jason Rantanen

Many empirical studies of Federal Circuit jurisprudence rely on searches of one of the leading legal databases such as Westlaw or Lexis.1 Relying on a search of a single database is potentially problematic, however, if the substantive content of the databases is not identical – in other words, if Lexis and Westlaw don't contain the same universe of cases, any claims about the results are necessarily limited by the dataset being used. 

In order to avoid this problem in connection with an empirical study of inequitable conduct that I'm working on, I recently performed a comparison of results obtained by a keyword search on Westlaw versus an identical search on Lexis.  This comparison revealed that although the data obtained from the two sources is largely comparable, small differences do exist that certain types of searchers may want to take into account.

The chart below shows the results, by year, produced by searching for the term "inequitable conduct" in the Federal Circuit databases for Lexis and Westlaw.2,3  In large part, the results suggest that there is relatively little variation between the two databases: in the context of this analysis, only 30 out of 681 (4.4%) Westlaw opinions were not found in Lexis and only 6 out of 657 (0.9%) Lexis opinions were not found in Westlaw.  Furthermore, in no instance did a precedential opinion appear in one database but not another.  Rather, all of the single-database hits were nonprecedential opinions.  In addition, nearly all of the nonprecedential opinions appearing in only a single database issued prior to 1991.   That said, there is a significant difference with respect to nonprecedential opinions for the period prior to 1991: nearly all the nonprecedential opinions from this time period are found in only one database.4  Thus, while it may not be efficient for most practitioners to run keyword searches on multiple databases, scholars conducting empirical research on Federal Circuit decisions, or individuals searching for older party-specific nonprecedential opinions, may want to be sensitive to the differences between the two databases.

Figure 1: Hits Resulting from Search Term "Inequitable Conduct" in Lexis and Westlaw5

 
Search comparison

1 See, e.g., Christopher A. Cotropia, "Determining Uniformity Within the Federal Circuit By Measuring Dissent and En Banc Review," 43 LOY. L.A. L. REV. 801, 811 (2010); Christian E. Mammen, Controlling the "Plague": Reforming the Doctrine of Inequitable Conduct,24 BERKELEY TECH. L.J. 1329, 1348 (2009);  Craig Allen Nard, Toward a Cautious Approach to Obeisance: The Role of Scholarship in Federal Circuit Patent Law Jurisprudence, 39 HOUS. L. REV. 667, 678 fn 40 (2002); Christian A. Chu, Empirical Analysis of The Federal Circuit's Claim Construction Trends, 16 BERK. TECH. L.J. 1075, 1092 (2001); but see R. Polk Wagner and Lee Petherbridge, Is the Federal Circuit Succeeding? An Empirical Assessment of Judicial Performance, 152 U. PA. L. REV. 1105, 1145 (2004) (using results from both Lexis and Westlaw).  In addition, some early empirical studies used the United States Patent Quarterly as their source (see, e.g., John R. Allison & Mark A. Lemley, How Federal Circuit Judges Vote in Patent Validity Cases, 10 FED. CIR. B.J. 435, 436 (2001)), which apparently contains some, but not all, nonprecedential patent decisions.  See e.g., Wirco, Inc. v. Rolock, Inc., 17 U.S.P.Q.2d 1084, 1990 WL 12901 (Fed. Cir. Feb. 14, 1990) as opposed to Mechanical Plastics Corp. v. Unifast Industries, Inc., 1988 WL 25422 (Fed. Cir. March 28, 1988).

For purposes of creating this chart, I used the additional limitation "CO(c.a.fed.)" to exclude CCPA and Court of Claims decisions, some of which are included in Westlaw's "ctaf" database.  In addition, I separately compared the results from a keyword search of the entire "ctaf" database to the results from the Lexis search in order to identify any Lexis-only hits that might have been excluded by the Westlaw court limiter.  This process did not reveal any such hits.

3 These results include every search hit that contained the term "inequitable conduct," regardless of the context.  It thus should not be viewed as reflecting any measure of substantive inequitable conduct determinations.  In addition, hits resulting from search terms appearing only in the database-specific casenotes were excluded, as were instances where the database contained duplicate entries of the case opinion or included a copy of a withdrawn opinion.   For more substantive analyses of inequitable conduct jurisprudence, see Lee Petherbridge, Jason Rantanen & Ali Mojibi, The Federal Circuit and Inequitable Conduct: An Empirical Assessment, ssrn id 1686102; Mammen, supra note 1.

4 In addition to double-checking the single-database cases against the search results of the other database, I also spot-checked several decisions against the Lexis/Westlaw case database as a whole by using terms from the parties' names and the Federal Reporter citation, where available.  Although in some instances this resulted in a hit, the contents of those hits were blank.  See, e.g., Air Products & Chemicals, Inc. v. Tanner, 738 F.2d 454 (1984) (nonprecedential) (no opinion in Westlaw; opinion in Lexis).

4 Although the results for 1997 appear equal, each database contained one opinion for that year that is not in the other database.

14 thoughts on “The Use of Online Databases for Legal Scholarship

  1. 14

    Oh wait, looks like I’m right, on every account

    I don’t even have to read anything else to know that this cannot be true.

    That be 6 – working at the Office and too busy to be making the big bucks.

    Keep bringing the chuckles 6.

  2. 13

    “Well, at least 6 is intelligent enough to realize that even on the odd chance he could actually get into law school, there’s no way he’d ever be able to get a job that would pay him enough money to pay back the loans. ”

    Lulz, oh no, I’m quite sure that I could. And that is probably the worst thing, it’d likely be one of the corporate billable hour megafirms which everyone is bad talking all the time.

    Competing with them is not a problem, but having to compete is ridiculous in a market that can be easily controlled.

    “I seriously doubt your offline personality is any different.”

    I seriously doubt you know me.

    Oh wait, looks like I’m right, on every account. Thanks for making that your last post lawlyertard old darkness.

  3. 12

    “…I’m well aware of how many lawlyertards think my online personality is a joke…”

    I seriously doubt your offline personality is any different.

  4. 11

    “I took an LSAT prep class and looked into the situation. Especially the financial situation. What I found was a lot of bad news.”

    Well, at least 6 is intelligent enough to realize that even on the odd chance he could actually get into law school, there’s no way he’d ever be able to get a job that would pay him enough money to pay back the loans.

    A man’s got to know his limitations. And 6 knows that he could never compete. Not even with the worthless hacks that glut the profession.

  5. 10

    6,

    This will be my last post to or about you.

    You have moved from mere ignorance to downright stu_pidity. I have never seen anyone more arrogant about their low level of intelligence.

    I realize that some post here to advocate their views, some to question and learn about the law and some for amusement. Posting to be the amusement, to be the fool, the class clown is one thing, but to relish and take pride in the absence of intelligence is too much.

    I pity you.

  6. 8

    “Coming from one who has failed in his attempts to become a “lawyertard”,”

    I don’t know who told you that I made “attempts to become a lawyertard”.

    I took an LSAT prep class and looked into the situation. Especially the financial situation. What I found was a lot of bad news.

    Oh look, more bad news.

    link to finance.yahoo.com

    It appears that you lawlyertards are incapable of policing yourself on even the most basic of levels. You glut up your profession with worthless hacks so that everyone is in hot competition even within your state-monopoly granted field.

    Let’s discuss who is a joke here.

    Oh, and to be sure, I’m well aware of how many lawlyertards think my online personality is a joke, but they’re lawlyertards, so what does it matter?

  7. 5

    6,

    Coming from one who has failed in his attempts to become a “lawyertard”, I find your attempted putdowns more damaging to you than to anyone else.

    You are worse than a court jester, as at least the court jester is aware of the role he plays, and quite frankly, you seem oblivious to what a joke you are.

    You would do everyone a favor and think a little bit before you post.

  8. 4

    Soon Google will kill both of them.

    I cannot imagine why you lawlyertards allowed these scams to start up in the first place.

  9. 3

    Those conducting research for District Court cases should always run the same search terms in lexis and westlaw.

Comments are closed.