We've heard for years about the invisible, hidden, deep or dark web -- that portion of the web that resides in databases and other formats not accessible to search engine spiders. One of the latest attempts to make this content searchable is DeepDyve, formerly known as Infovell.
DeepDyve offers a federated search of a wide variety of content, some of which is free and some requires payment to the publisher. Sources include MEDLINE, Clinical Trials, PubMed Central, BioOne and SAGE Publications - some heavy-hitters. Searchers can limit their search to various slices of this content, such as legal, business & finance, life sciences, or clean tech and energy.
What sets DeepDyve apart is how it handles text and queries. The founders of the company worked on the Human Genome Project prior to starting Infovell, and they approach search differently than most. For DNA research, scientists must take small snippets of genetic material and match them together. To the information processing algorithm, the actual meaning of the terms didn't matter; it's looking for patterns. DeepDyve takes that same language agnosticism to offer a very different approach to textual analysis than the usual syntactic analysis.
Like Yahoo's Y!Q, DeepDyve is designed to work with a block of text rather than just a few search terms to find useful information. Given its founders' background, it's not surprising that DeepDyve can even handle searching for chemical formulas; in fact, you can point it to a collection of articles you have selected from a prior search and say, in essense, "These are all helpful. Find me more like them."
DeepDyve requires (free) registration for its basic version; the Pro version, which costs $45/month, includes additional search and display features but no additional content.