Internet Search Services
Loosely organizing the ’net
The vast amount of information available on the Internet can be dizzying. Some authorities estimate the number of documents on the Internet to be in the range of 800 million. Others say the number is unknowable. Fortunately, there are tools available that will sort through the mass of information: search engines or search directories.
Search engines collect information from Web sites and then, more or less, just dump that information into a database. There's more information to choose from in a search engine, but it's more difficult to retrieve relevant information.
Search directories try to impose some sense of order on the information they collect and you're more likely to find information relevant to your research topic, but they don't offer the massive amounts of information that you would find with a search engine. The sites collected are viewed by humans who make decisions about what subject categories the sites might fit into.
Search engines are really just massive databases in which information from Internet documents are stored. The information in these databases is collected using a computer program (called a "spider" or a "robot") that scans the Internet and gathers information about individual documents. These special programs work automatically to find documents or they are asked by a creator of a Web site to visit the site to be included in a database.
When you do a search in a search engine, the order in which the results are listed also varies between search engines. Many search engines list the results using relevance ranking. Factors such as:
- how often your search terms are on the Web page;
- where they are located on the page; and,
- how many other Web pages link to the page
...influence how high on the list of hits a page is listed. Many search engines allow Web sites to pay to have their pages listed higher in the results.
There are hundreds of these search engines available on the Web, but they all work in unique ways to collect and organize the information found. The information from Web sites might be gathered from all the words in a site, just the first few sentences in the body of a site, or only from the title or metatags (hidden descriptors of a site's content). Different search engines collect different information, that's why you'll get different results from the same search from different search engines.
Directories are best used when you are looking for information that is easily classified, such as "Universities and Colleges in Georgia." You can find the information you need without even typing in a search, but by browsing the directory, starting with a very broad subject category (Education) and working your way through the directory until you come to individual listings for schools in Georgia. You can do the usual search as well, but directories don't collect the same range of sites that a search engine would so you wouldn't be tapping into the wealth of information that you can get from a search engine.
GALILEO also has a database of useful Web sites that are evaluated by educators. These sites are not submitted by the developer nor are they harvested by spiders. They are chosen deliberately for their usefulness for research in the curriculum of the University System of Georgia.
These type of search services offer sort of a "one-stop shopping" to the Internet. You can form one search and a metasearch service will send the search to several other search engines and directories simultaneously so that you get the results from all of them in one place. The only problem with this is that you only get the first few results from each listing. If the site you're looking for happens to be listed in the 10th position in a search services results list and the metasearch engine only provides the first 5 results from that list, then you won't find the site you need. If you're only trying to get a general idea of what information is available on the Web, then a metasearch engine would be a good place to start.
The following are external links and will open in pop-up windows: