Search Engines Don't Overlap

Search Engine Watch reports on a new study which found that the results from most search engines do not overlap with other search engines. It found that for first page search results, 84.9% of total results are unique to one engine. The search was conducted by Dogpile, a metasearch engine that displays results from multiple search engines.
This finding is important for researchers to understand. Relying on just one search engine can be detrimental. While you may not find what you need in your favorite search engine (or subscription database, or book, or journal. . .), you might just turn it up with another.
Source: Robert Ambrogi’s Law Sites