Reducing False Positives in Lexis/Westlaw Searches:
A while back, I briefly mentioned ATLEAST, NOT W/, and SY,DI() searches, and a lawprof friend of mine wrote me,
You can probably do a big favor to a lot of VC readers, including me, by explaining [these search options].
So here's a brief explanation.
All three of these help reduce the number of false positives returned by your Lexis (ATLEAST, NOT W/) or Westlaw (SY,DI()) search, without much increasing false negatives.
1. Lexis's pretty bad Index feature doesn't help much here -- try searching for ATLEAST and NOT W/, and you'll get nothing -- but if you look in the online help under Searching/Using Terms and Connectors/Connectors, and you'll see:
The NOT W/n connector tells the research software to find documents in which at least one occurrence of the first search term is not within n searchable words of the second term....
EXAMPLE: ... rico NOT W/2 puerto
This finds documents that have at least one occurrence of "rico" (possibly standing for Racketeer Influenced and Corrupt Organizations Act) that has no occurrences of the term "puerto" within two searchable words of it. This does not mean the same document could not have these two words within two searchable words of each other elsewhere.
So NOT W/ is better than AND NOT -- rico AND NOT puerto will miss cases that have both Puerto Rico and a standalone RICO, but rico NOT W/2 puerto will catch them.
2. The online help, if you properly navigate it, will also tell you about ATLEAST: Searching for, say, atleast10(copyright) will find all documents that contain the word copyright at least 10 times.
3. SY,DI() is a Westlaw connector: Searching (using terms and connectors, not natural language searching) for SY,DI(search terms) finds all cases that contain the search terms in the Synopsis -- usually a paragraph that appears at the start of the case and that was written by West, though for some courts by the court itself -- and in the Digest entries for the case. This will thus focus on what West has seen as the heart of the case's holdings, and skips casual mentions in the facts or in a parenthetical briefly discussing some other case.
Note that SY,DI() searching will exclude many unpublished cases, for which West often doesn't prepare synopses and digests, but that may be part of your goal.
If you folks have other such research tips to add, either as to Westlaw or Lexis, please post them in the comments.