Google is a great search engine, but it misses a vast amount of information that is generally "invisible" to its Internet spiders and crawlers -- most of tucked away in databases and dynamically-generated pages. These hidden gems are often referred to by search analysts as the "invisible Web" or "deep Web."

One way to mine the invisible Web is to use a specialized deep Web search engine or directory. These allow you to directly search thousands of searchable databases and specialty search engines in one step. I generally don't find these specialized search engines all that useful for genealogy research, but occasionally they uncover a gem or two.

The slower but more useful method for mining the deep Web is something you probably already do as part of your standard genealogy research. The deep Web includes databases and collections searchable through archives, libraries and universities, many of which can best be searched manually. Many major free databases such as the IGI and EllisIslandRecords are part of this so called "invisible web" and their data won't come up in most standard search engine searches.

The trick to using this "invisible" data is to learn what resources might have information pertinent to your area of research. Many public libraries and state archives, for example, have free, searchable databases. There you may be able to find obituaries, land grants, wills, marriage indexes and other genealogical gems. In France, for example, a large number of departmental archives have placed birth, marriage, death and census records online. Become familiar with the repositories and organizations in your areas of research that may have placed genealogical records online, and make them a regular stop in your research.