Halevy, who heads the "Deep Web" search initiative at Google, described the "Shallow Web" as containing about 5 million web pages while the "Deep Web" is estimated to be 500 times the size. This hidden web is currently being indexed in part by Google's automated systems that submit queries to various databases, retrieving the content found for indexing. In addition to that aspect of the Deep Web - dubbed "vertical searching" - Halevy also referenced two other types of Deep Web Search: semantic search and product search.

Google wants to also be able to retrieve the data found in structured tables on the web, said Halevy, citing a table on a page listing the U.S. presidents as an example. There are 14 billion such tables on the web, and, after filtering, about 154 million of them are interesting enough to be worth indexing.

Can Google Dig into the Deep Web?

The question that remains is whether or not Google's current search engine technology is going to be adept at doing all the different types of Deep Web indexing or if they will need to come up with something new. As of now, Google uses the Big Table database and MapReduce framework for everything search related, notes Alex Esterkin, Chief Architect at Infobright, Inc., a company delivering open source data warehousing solutions. During the talk, Halevy listed a number of analytical database application challenges that Google is currently dealing with: schema auto-complete, synonym discovery, creating entity lists, association between instances and aspects, and data level synonyms discovery. These challenges are addressed by Infobright's technology, said Esterkin, but "Google will have to solve these problems the hard way."

Also mentioned during the speech was how Google plans to organize "aspects" of search queries. The company wants to be able to separate exploratory queries (e.g., "Vietnam travel") from ones where a user is in search of a particular fact ("Vietnam population"). The former query should deliver information about visa requirements, weather and tour packages, etc. In a way, this is like what the search service offered by Kosmix is doing. But Google wants to go further, said Halevy. "Kosmix will give you an 'aspect,' but it's attached to an information source. In our case, all the aspects might be just Web search results, but we'd organize them differently."

Yahoo Working on Similar Structured Data Retrieval

The challenges facing Google today are also being addressed by their nearest competitor in search, Yahoo. In December, Yahoo announced that they were taking their SearchMonkey technology in-house to automate the extraction of structured information from large classes of web sites. The results of that in-house extraction technique will allow Yahoo to augment their Yahoo Search results with key information returned alongside the URLs.

In this aspect of web search, it's clear that no single company has yet to dominate. However, even if a non-Google company surges ahead, it may not be enough to get people to switch engines. Today, "Google" has become synonymous with web search, just like "Kleenex" is a tissue, "Band-Aid" is an adhesive bandage, and "Xerox" is a way to make photocopies. Once that psychological mark has been made into our collective psyches and the habit formed, people tend to stick with what they know, regardless of who does it better. That's something that's a bit troublesome - if better search technology for indexing the Deep Web comes into existence outside of Google, the world may not end up using it until such point Google either duplicates or acquires the invention.

Still, it's far too soon to write Google off yet. They clearly have a lead when it comes to search and that came from hard work, incredibly smart people, and innovative technical achievements. No doubt they can figure out this Deep Web thing, too. (We hope).