"O brave new world, That has such people
--William Shakespeare, The Tempest, 1611-12
Subject directories, unlike search engines, are created and
maintained by human editors, not electronic spiders or robots.
The editors review and select sites for inclusion in their
directories on the basis of previously determined selection
criteria. The resources they list are usually annotated.
Directories tend to be smaller than search engine databases,
typically indexing only the home page or top level pages of a site.
They may include a search engine for searching their own directory
(or the web, if a directory search yields unsatisfactory or no
When you initiate a keyword search of a directory's contents,
the directory attempts to match your keywords and phrases with those
in its written descriptions.
Subject directories come in assorted flavors. There are general
directories, academic directories, commercial directories, portals
and now, vortals.
Portals are directories that have been created or taken over by
commercial interests and then reconfigured to act as gateways to
the web. These portal sites not only link to popular subject
categories, they also offer additional services such as email,
current news, stock quotes, travel information and maps.
Vortals, or vertical portals, (See Lesson 4 for
examples) are subject-specific
directories, as opposed to the broader, more generalized smorgasbord
of subjects and other links commonly found in portals.
NOTE: Today, the line between subject directories and search engines
is blurring. Most subject directories have partnered with search
engines to query their databases and search the web for additional
sources, while search engines are acquiring subject directories or
creating their own.
Two subject directories have partnered with and developed their own
search engines that are very powerful. You will see them listed in both
the search engine and the subject directory categories. Check out the different
engine and directory "looks" below:
Directory editors typically organize directories hierarchically
into browsable subject categories and sub-categories. When you're
clicking through several subject layers to get to an actual Web page,
this kind of organization may appear cumbersome, but it is also the
directory's strength. Because of the human oversight maintained in
subject directories, they have the capability of delivering a higher
quality of content.
They may also provide fewer results out of context
than search engines.
Unlike search engines, most directories do not compile databases of
their own. Instead of storing pages, they point to them. This
situation sometimes creates problems because, once accepted for
inclusion in a directory, the Web page could change content and
the editors might not realize it. The directory might continue
to point to a page that has been moved or that no longer exists.
Dead links are a real problem for subject directories, as is a
perceived bias toward e-commerce sites.
Like the yellow pages of a telephone book, subject directories
are best for browsing and for searches of a more general nature.
They are good sources for information on popular topics,
organizations, commercial sites and products. When you'd like to
see what kind of information is available on the Web in a particular
field or area of interest, go to a directory and browse through
the subject categories.
Portals (subject directories serving as home pages)
Select any two subject directories listed above (not the portals) and follow the subject
categories -- do NOT use the search box -- to search for information on:
(HINT: Find the Health link and start there.) Notice the differences in how
the human editors organize their sites.
Gateways & Databases
[Table of Contents]
[Gateways & Databases]
[Evaluating Web Pages]
Last updated by E. Chamberlain, Thursday September 07, 2006