2.3.1. Understanding Taxonomies

A directory differs from the index used by a search engine because a directory uses a structured way to categorize sites, sometimes called a taxonomy. In addition, sites are included in a particular category in the ODP and Yahoo! directories only after they have been reviewed by human editors. You can search within directories (just as you can search in a web index, such as the one compiled by Google). But it's common to use a directory, following its taxonomy by drilling down through subjects to find what you want. For example, suppose you wanted to find resources related to alternative photo processes, such as creating daguerreotypes (a nineteenth-century print technology). Using the Open Directory taxonomy, shown in Figure 2-2, you would drill down through the following categories: Arts -> Photography -> Techniques and Style -> Alternative Processes.

"You can think of the index of the Web compiled by search engines such as Google as being like the index to a nonfiction book. In contrast, a taxonomic directory is much more like the table of contents to the book: it is organized according to the structure of the book, and you can drill down by part, chapter (within the part), heading (within the chapter), and subtopic to find the information you need."

Figure 2-2. You can find "Alternative Processes" by drilling down through Arts, Photography, and Techniques and Styles

Back To Index