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What the Google Directory IsAnd What It Isn'tThe Google Directory, shown in Figure 3.1, is a relatively small database of web page listings. (Small compared to the main Google database, that is.) Each listing in the Google Directory is handpicked by a team of human editors; the listings are then annotated and organized into relevant topic categories. You can browse the directory via category, or search for specific terms. Figure 3.1. The Google Directoryready to browse (by category) or search.
To access the Google Directory, click the More link on the Google home page and then select Directory on the following page. Alternatively, you can go directly to the Google Directory by entering directory.google.com in your web browser. Why a Directory Isn't a Search Engine, and Vice VersaMost users don't know the difference between a search engine and a directory. After all, both directories and search engines contain lots of web page listings, and both are searchable. What's the diff? The difference between a directory and a search engine is in how the listings are compiled. As you learned in Chapter 1, "Inside Google," Google's search engine works by sending automated GoogleBot software out to crawl the Web, and then uses a proprietary formula to match the pages to users' search queries. This process guarantees a huge number of results for most queries, but it's all very sterile and automated. There's no good way to truly judge the content or quality of a page; it's all about numbers. In contrast, a directory is assembled by a team of human editors. That's right, human beingsnot machines. The human beings find and evaluate pages on the Web, annotate the page listings, and organize them into relevant categories. Unlike computers, human beings can make qualitative judgments about a page's content, and can evaluate the actual meaning of the page. It's not about numbers; it's about content. All of which means that a directory is likely to have higher-quality results than a search engine. It's also likely to have fewer results (far fewer, when compared to Google's gargantuan search index) because of the need to closely examine each individual page before it's added to the directory. Where the Google search index includes billions of listings, the Google Directory contains just 5 million listingsless than 1/10th of 1% of what's in the search index. It's the difference between casting a wide net (in the case of Google's search engine) and taking everything that's caught inside, and dropping a single fishing line in the water (in the case of the Google Directory) with the intent of catching a particular type of fish. You get lots of fish with the wide net approach, but you get the fish you want by using a rod and reel. The other big difference between a directory and a search engine is organization. A search index has none; those billions of pages are dumped into one big database, with no sense of order. A directory, on the other hand, is all about order; the human editors not only pick the web pages to be included, they also organize the sites into logical categories. So where you can't browse a search index, you can browse a directory, simply by clicking through the hierarchy of categories and subcategories. Since they look at every page included in the directory, the directory's human editors also have the opportunity to annotate those pages. Browse through a directory's category listings and you're likely to see summaries, reviews, and comments about the web pages listed. These annotations are not automatically generated from the page's content; they're added by the editors, in what amounts to a very human touch. A directory's human editors also provide one other important functionthey continually check for and remove dead links. This is something that search engines don't always do well; a human being is going to be more diligent about keeping the listings updated. So what are the final differences between a search engine and a directory? Table 3.1 summarizes them:
How the Google Directory Is AssembledThe Google Directory works like most other web directories, such as the Yahoo! Directory (dir.yahoo.com), LookSmart (www.looksmart.com), or Best of the Web (www.botw.org). Thousands of human editors sort through sites submitted by users, as well as do their own web browsing, to find the sites included in the directory. Once a web page has been accepted for inclusion, the editors write a brief review/overview of the page, and assign it to a topic category. It's a totally manual process; there are no bots crawling the Web or linguistic programs excerpting page contents. All the work is done by hand. But here's the thing. Google doesn't assemble it's own directory. No, the Google Directory is actually a customized version of a third-party directory called the Open Directory Project. (Figure 3.2 shows the Open Directory home pagelook familiar?) Figure 3.2. The Open Directorythe basis for the Google Directory.
Google takes the Open Directory listings and grafts the Google interface and search engine on top of them. So, while the listings in the directory are assembled by Open Directory editors, they're ranked using Google's PageRank technology. If you compare a category in the Google Directory with the same category in the Open Directory, the listings will be the same, but arranged differently. Note You can access the Open Directory directly at www.dmoz.org. (DMOZ is an acronym for Directory Mozilla, which reflects the directory's loose association with Netscape's Mozilla web browser.) The good thing about Google using the Open Directory is that it's perhaps the largest and highest-quality web directory available. The Open Directory Project is a huge undertaking, hosted and administered by Netscape (part of America Online), with more than 70,000 volunteer editors submitting reviews and rankings of websites and pages. Google made a good choice in partnering with the Open Directory; the combination of Open Directory listings with Google's interface and PageRank rankings makes the Google Directory the easiest-to-use and most useful directory on the Web. It's the use of Google's PageRank technology that makes the Google Directory so easy to use. Instead of just browsing through the category listings (which you can do if you want), Google's search technology lets you search the directory listings the same way you search Google's search index. The listings in the directoryand thus the results of your queryare ranked according to relevance, thanks to the use of PageRank. The most relevant sites always appear near the top of the listings, which they don't necessarily do if you access the raw Open Directory listings. Tip To submit a web page for possible inclusion in the Open Directory/Google Directory, follow the instructions at www.dmoz.org/add.html. To volunteer your services as an Open Directory editor, navigate to any category in the directory that interests you, and then click on the Become an Editor link at the bottom of the page and follow the onscreen instructions from there. Why You'd Want to Use the Google Directory Instead of Google's Web SearchNow that you know the difference between Google's standard search engine and the Google Directory, which should you use for your searching? Tip You don't have to worry about the Google Directory containing results that don't appear in a standard Google web search. Google's search index includes all the entries in the Google Directory, in addition to the pages added by the GoogleBot crawler. Here are some tips:
The bottom line is that if you want a lot of results, and don't mind wading through the chaff to find a little wheat, use the standard Google search engine. But if you're tired of search results that aren't quite what you're looking for and want more qualified results, consider using the Google Directory. In other words, if you want quantity, use the standard Google search engine. If you want qualityor a good category overviewuse the Google Directory, instead.
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