10,000 documents is an awful lot. Truly a low precision, high recall search. But sometimes, one starts off searching very broadly because Westlaw and Lexis Advance provide a “search within results” option to narrow down initial search output. While I do not perform many broad searches in Westlaw, I have never once seen a figure higher than 10,000 documents in my search results. I have, however, seen “10,000+” documents in equally broad Lexis Advance searches on the same topic. Unfortunately 10,000 documents appears to be a search results limit in Westlaw.
If an initial search pulls up 10,000 documents in Westlaw, there is no reason to believe all Westlaw documents identified by one’s search are really all the potentially relevant documents in the Westlaw database. Searching within the initial 10,000 documents search results would be, therefore, based on a seriously flawed subset of the Westlaw database, one defined by West Search, not one’s search logic. This is not the case in Lexis Advance where a broad search may yield 10,000+ documents for searching within initial results. If this is indeed a flaw in West Search’s output, one must conclude that Lexis Advance offers more comprehensive searching of its database than Westlaw. — Joe