Vertical Search Engines

A vertical search engine searches a specific industry, topic, type of content (e.g., travel, movies, images, blogs, live events), piece of data, geographical location, and so on. It may help to think of vertical search as a search for a particular niche. Some of this content cannot be found, or is difficult to find, on general search engines. For this reason, the topic of vertical search is closely related to that of the deep Web. Be sure to visit the tutorial on The Deep Web for a fuller discussion of this topic.
To find a vertical search engine, you can use a general search engine and try to find a search site dedicated to a particular type of content, for example medical search, job search, and so on.

When to use a vertical search engine

• When your topic is focused on a specific topic, industry, content type, geographical location, language, etc.
• When you're having difficulty locating what you want on general, meta, or concept categorizing search engines

A few examples of vertical search engines

There are so many example out there on so many topics - it's endless! This page will list just a very few. Notice how some cover broad topics while others are of narrower interest.
Topical search engines

~ MedNar and PubMed
~ ScienceResearch.com and World Wide Science

Industry search engines

~ BizNar, the world of business
~ Industry Search, a search for industrial supplies limited to Australia and New Zealand
~ PaperPundit, searching the pulp and paper industry created with Google Custom Search
~ Stock Screener from Yahoo!

Image search engines

~ Picsearch
~ Library of Congress Prints & Photographs Online Catalog
tip! A good source for more of these tools can be found in a 2008 posting on the ReadWriteWeb blog, Digital Image Resources on the Deep Web.

News search engines

~ Alltop
~ NewsNow

Blog search engines

~ Google Blog Search
~ Technorati

Full text books and articles

~ Google Book Search
~ Google Scholar
~ The Online Books Page
~ Project Gutenberg

Social Web real time search

~ Twitter Search and Twitscoop for Twitter content
~ FriendFeed Search for social networking activities

Concept Categorizing Search Engines

A concept categorizing search engine organizes results into topical categories or concepts. These concepts are derived from the contents of your search results. This arrangement may be thought of as a horizontal layout of results, in contrast to a single, vertical list of results that you find on such search engines as Google. Most concept processing engines also offer a vertical list of results. The concept categories are an added bonus.
When you encounter concept categories, you can first review them to determine if the results are relevant to your search. If not, you can try another search. Or perhaps your results are fine, but the categories themselves could be better! If the categories look useful, you can select the ones of interest and examine their contents. Concept categories can also help you learn about your topic.
There aren't as many concept categorizing search engines as there once were. This is a shame, because this type of search engine can be very helpful to your research.

When to use a concept categorizing search engine

• When your search is a general one and you want to learn about the component concepts of your topic
• When you know very little about your topic and want help in identifying its scope and content
• When your topic is obscure
• When you are having trouble finding what you want when scanning a single list of search results

Examples of a concept categorizing search engine

Here is an example of concepts retrieved from a Quintura search on "global warming" on Quintura. The concepts are laid out in a tag cloud, very popular on the Web these days.