Keyword searching is a type of searching you are probably already familiar with. It is how you would typically search web search engines like Google. You think of words or phrases relevant to your topic and enter them in the search box. When searching the library catalog, your keywords and phrases are searched for in all of the fields of the catalog record. It is important to remember that because we are using natural language, the word you use to describe a subject may not be the same word used by all of the authors in the field.
Types of Search Engines:
There are three types of search engines: crawler-based (or spider-based), human-powered directories and hybrid search engines.
Crawler-based search engines such as Google, Yahoo and Bing, compile their listings automatically. They “crawl” or “spider” the web, and people search through their listings. These listings are what make up the search engine’s index or catalogue. You can think of the index as a massive electronic filing cabinet containing a copy of every web page the spider finds. Because spiders scour the web on a regular basis, any changes you make to a website, or links to or from your own website, may affect your search engine ranking.
Crawler-based search engines are good when you have a specific search topic in mind and can be very efficient in finding relevant information in this situation. However, when the search topic is general, crawler-base search engines may return hundreds of thousands of irrelevant responses to simple search requests, including lengthy documents in which your keyword appears only once.
Human-powered directories, such as the Yahoo directory, Open Directory and LookSmart, depend on human editors to create their listings. Typically, webmasters submit a short description to the directory for their websites, or editors write one for the sites they review, and these manually edited descriptions will form the search base. Therefore, changes made to individual web pages will have no effect on how these pages get listed in the search results.
Human-powered directories are good when you are interested in a general topic of search. In this situation, a directory can guide and help you narrow your search and get refined results. Therefore, search results found in a human-powered directory are usually more relevant to the search topic and more accurate. However, this is not an efficient way to find information when a specific search topic is in mind.
A hybrid search engine is a computer search engine device that incorporates the use of directory and crawler based results. There are various types of hybrid search engines available on the internet, for instance Google and Yahoo.
Tagging is essential to finding what you need in an article. Many articles have “tags” on them, or a series of words that can be found within the article itself. It makes it easier for people to find certain topics.