Google Directory

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/ . Unlike the results at the standard Google Web Search, the collection of URLs at the Open Directory Project is gathered and maintained by a group of human volunteers rather than automatic algorithms, but Google does add some of its own Googlish magic to it.

Google's Web Search indexes billions of pages, which means it isn't suitable for all searches. When you have a search that you can't narrow downfor example, if you're looking for information on a person about whom you know nothingbillions of pages will get very frustrating very quickly.

One thing you'll notice about the Google Directory is how the annotations and other information vary between categories. This is because the information in the directory is maintained by a small army of thousands of volunteers who are each responsible for one or more categories. For the most part, annotation is pretty good.

But you don't have to limit your searches to the Web. 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 five million URLs. This makes it a much better search for general topics.

Beside most listings, you'll see a green bar. The green bar is an approximate indicator of the site's PageRank in the Google search engine. (Not every listing in the Google Directory has a corresponding PageRank in the Google web index.) Web sites are listed in the default order of Google PageRank, but you also have the option to list them in alphabetical order.

Search and Browse

If you were interested in looking at sites about child psychology, you might try a search at http://search.google.com with the query child psychology. You would find thousands of sites in the search results, along with news articles about child psychology, college papers about the topic, and even pages that mention the terms child and psychology without relating to the topic. But browsing the Child Psychology category in the Google Directory ( http://directory.google.com/Top/Science/Social_Sciences/Psychology/Child_Psychology/ ) gives you hundreds of links selected by Open Directory volunteers as being relevant to the topic.

There are two different kinds of shoppers, and they illustrate the difference between searching and browsing. Some shoppers know exactly what they're after, and they want to find a store with the item, locate the item, and purchase it as quickly as possible. As with a web search, it helps to know a bit about what you're looking for if this is your style.

Other shoppers want to explore a particular store, see what the store offers, and choose an item if the right one comes along. This style of browsing is suited for people who want to get a larger survey of items in a particular category before they necessarily know what they're looking for.

There are still times when you need to search the directory, and Google has provided a couple ways to accomplish this.

Find The Google Directory

When you're searching on Google's web index, your overwhelming concern is probably how to reduce your list of search results to something manageable. With that in mind, you might start with the narrowest possible search.

That's a reasonable strategy for the web index, but because you have a narrower pool of sites in the Google Directory, you want that search to be more general.

For example, say you were looking for information on author P. G. Wodehouse. A simple search on P. G. Wodehouse in Google's web index gets you over 1,100,000 results, possibly compelling you to immediately narrow your search. But doing the same search in the Google Directory returns only 176 results. You might consider that a manageable number of results, or you might want to carefully narrow your results further.

Because the Google Directory is a far smaller collection of URLs, ideal for more general searching, it does not have the various complicated special syntaxes for searching that the Web Search does. However, there are a couple of special syntaxes that you should know about:

intitle:

Just like the Google web special syntax, intitle: restricts the query word search to the title of a page.

inurl:

inurl: restricts the query word search to the URL of a page.

The Directory is also good for searching for events. A Google web search for Korean War will find over 24 million results, while searching the Google Directory will find just over 138,000. This is a case where you will probably need to narrow your search. Use general words indicating what kind of information you wanttimeline, for example, or archives, or lesson plans. Don't narrow your search with names or locations; that's not the best way to use the Google Directory.