This article explains some important details for effectively searching e-discovery:
"[M]isplaced confidence in the power of word searches can seriously hamper electronic data discovery. Perhaps because keyword searching works so well in the regimented realm of automated legal research, lawyers and judges embrace it in EDD with little thought given to its effectiveness as a tool for exploring less-structured information. Too bad, because the difference between keyword searches that get the goods and those that fail hinges on thoughtful preparation and precaution.
TEXT TRANSLATION
"Framing effective searches starts with understanding that most of what we think of as textual information isn’t stored as text. Brilliant keywords won’t turn up anything if the data searched isn’t properly processed.
[snip]
"Lots of evidence we think of as textual isn’t stored as text, including fax transmissions, .tiff or PDF documents, PowerPoint word art, CAD/CAM blueprints and Zip archives. For each, the search software must process the data to insure content is accessible as searchable text.
"Be certain the search tool you or your vendor employ can access and interpret all of the data that should be seen as text."