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DMOZ: Open Directory Project

Subcategories

Introduction

Hierarchical category systems like the ODP traditionally have been called classification systems. Taxonomy and ontology are additional terms used to describe the work of organizing categories. The goal in developing a category structure is to create a system that allows people to easily find material.

The ODP follows a peer review process, so no individual editor owns his or her category. Even if you are the only editor listed in a category, there will be other editors who will be able to edit and add sites there. These editors include parent category editors, editalls, metas and staff.

Editors have learned from experience that communication (e.g., by e-mail or by posting proposed changes in the appropriate editor forum) is critical to a successful editing process. When you want to make changes such as creating subcategories, or moving sites between categories, you should communicate with other editors before going ahead. Even if you are the sole editor of a category, you should communicate changes to parent category editors.

Creating Subcategories

Generally, subcategories may be helpful when the number of links exceeds 20, but creating subcategories when there are fewer than 20 links generally will hinder users' ability to find the desired information. Once a category has 20 or more links, editors may see groups of links that can be easily organized by subtopic.

If you edit outside of the Regional branch, you should subcategorize and organize sites by topic whenever possible. When you have exhausted all possible ways of organizing sites by topic, you may organize sites by geographic area or by an alphabet bar, whichever is appropriate. Generally, organizing sites into alphabet bars should be done as a last resort.

Alternatively, you may decide to keep all your sites in one category. For example, the category Business: Transportation and Logistics: Trucking: Truck Sales: Used: North America contains 50+ links to sites selling used trucks. It is difficult to break this category up into topical subdivisions based on the type of product, since all sites seem to offer the same or very similar products and services.

If you are listed as editor of a category, you can automatically also edit in any subcategories or sub-subcategories underneath it, as a "parent editor". You don't need to name yourself as editor of subcategories that you create, and it is recommended that you not do so, unless it is a "pet" category or special interest of yours, where you expect to lavish lots of time and attention on building it up, or if you are acting as part of a planned reorganization that will lead to the subcategory being moved elsewhere, and you wish to continue to maintain the category after it is moved. Leaving smaller categories without a listed editor serves to attract new editors to join the ODP, and current editors to branch out into new areas. In extreme cases editors may be asked to resign from over-extensive lists of categories that they have editing access to "from above."

Choosing Subcategory Names

The ODP currently does not use a prescribed thesaurus for assigning subcategory names, however it is suggested that you utilize the Preferred Terms list where possible. The following guidelines may be useful in assigning names that will ensure consistency across the ODP and prevent duplication of categories.

Note: Regional editors have developed their own prescribed and recommended list of subject subcategories to be used under geographic locations in the Regional branch only. Please see the Regional Guidelines for more information.

Duplicate and Related Categories

An effective editor will search and/or browse through the ODP in areas inside and outside his or her top level category to find areas of potential duplication. Questions editors have found useful to consider include the following: Is my subcategory cross-disciplinary, and if so, what other areas could resources in my subcategory be classified under? If there is a subcategory in another area of the ODP that is similar to my subcategory, should I create a Related Categories link? Should I create an @link (See also @Links below)

Topical Subcategory Names vs. Form Subcategory Names

Characteristics of Helpful Subcategory Names

Helpful subcategory names

Directories and Resources

Several categories in the ODP have been created in order to list sites that are web directories or contain resources covering a particular subject area. The terms resources and directories are at times used interchangeably; however, they should be used to classify two types of sites that are quite different. The following is how the ODP defines the scope of Directories and Resources categories.

Directories

Use to classify sites that contain alphabetical or classified lists of resources covering a particular subject area.

Resources

Use to classify sites whose purpose is to provide a comprehensive overview of a particular subject area. Resource sites typically include general information about a topic, and provide directories, FAQs, chats and forums, publications etc. Most resource sites should be listed in the main topical category. If the main category gets too large, the sites may be placed in a subcategory called Resources.

Changing the Name and Location of a Subcategory

Only editors with catmv (category move) permissions can rename and move categories. Simple changes, such as typographical errors and those that bring category names in line with templates and category guidelines, can be requested by posting to the "Category Move/Rename/Delete Requests" thread in the appropriate forum.

Complex changes such as those affecting hierarchy and ontology should be discussed and agreed upon by the editing community. Follow these tips and advice when reorganising category hierarchies: Reorganising Categories.

Do not manually make category changes by creating a new category, moving sites from the old category to the new destination category, and then deleting the old category. The ODP loses valuable logs and category navigation integrity when this happens. A catmv by an editor with appropriate permissions is the most efficient way to move large numbers of links. Editors found making manual category moves (manual catmvs) may have their editing permissions revoked. For further information, see The Perils of the Manual Category Move (catmv).

Regional Subcategories

The Regional branch of the ODP is the place to list sites focusing on a specific geographic region. In general, the subject branches of the ODP contain sites that do not have a particular geographic focus and/or the sites are of global interest. If you are interested in creating a directory for regional and local resources, then you should consider becoming an editor in the Regional branch. A local resource is one that covers a limited area, usually within a country's state, province, or other equivalent administrative area (e.g. locality, metro area, county, region). Editors may create regional subcategories when no other type of organization will work. Please read the FAQ - Creating and Maintaining Regional Subcategories Under Topical Categories for more detailed instructions.