Google Hacks

Google Directory

Google has a searchable subject index in addition to its 2 billion page web search.

Google’s web search indexes over 2 billion pages, which means that it isn’t suitable for all searches. When you’ve got a search that you can’t narrow down, like if you’re looking for information on a person about whom you know nothing, 2 billion pages will get very frustrating very quickly.

But you don’t have to limit your searches to the web search. Google also has a searchable subject index, the Google Directory, at http://directory.google.com. Instead of indexing the entirety of billions of pages, the directory describes sites instead, indexing about 1.5 million URLs. This makes it a much better search for general topics.

Does Google spend time building a searchable subject index in addition to a full-text index? No. Google bases its directory on the Open Directory Project data at http://dmoz.org/. The collection of URLs at the Open Directory Project is gathered and maintained by a group of volunteers, but Google does add some of its own Googlish magic to it.

Figure 2-1. The Google Directory

As you can see, the front of the site is organized into several topics. To find what you’re looking for, you can either do a keyword search, or “drill down” through the hierarchies of subjects.

Beside most of the listings, you’ll see a green bar. The green bar is an approximate indicator of ...