Search Engines



Making Sense Of Search Engines

We know that there is a lot of information on the net. But how do you find the material you need? It’s a bit like finding one good book left in a rubbish dump!

There are a number of search tools. These are often called “search engines”. However, there are some quite different tools we call search engines which are, in fact, not search engines at all.

Yahoo for example is not a search engine at all. It’s a “Web [Subject] Directory” which is quite different.

As well as search engines and Web directories, there are

  • meta search engines
  • “deep” web search engines
  • newsgroup searches
  • mailing list searches
  • specialty search engines
It is however, often hard to tell them apart.
They often have more than one of the above functions as well as their main function.
 

Search Engines
By which information is found and sorted by machines
Search engines are maintained by machines and they attempt to index everything on the web and then allow you to search the created database. They use special programs that explore the web. This is a very difficult task because there are billions of pages on the word wide Web alone and these are constantly being added to and also many pages disappear.
Some good search engines are:
 

Web Directories
Sometimes called "subject directories" in which information is found and sorted by people.
Web directories make no attempt to index the whole web. Instead these services use categories and then add smaller and smaller subcategories. They work best when you browse through the categories and drill down until you find the sites you need.
Web directories are hand picked by humans. Because of this, the results can be old as it takes a while for people to sort the pages.
The best directories are probably yahoo.com and one of my favourites, askjeeves. I like askjeeves or better still askjeevesforkids, [ajkids.com ] because you can ask for results using questions. If it does not know the question ajkids will try to ask other helpful questions. You can also get a more local version. You can also get Australian versions of Yahoo and Looksmart.
Some of the best are

Metasearch Engines
Metasearch engines do not crawl the web like search engines but use the information in the data bases of search engines.

They search through a number of search engines at once and display the information from these search engines. A good example of this is the search you use from SINA. Often you can see from the results, which search engine is giving you the best answers to your question. These are usually very fast and because they only take the first few answers, usually give you only the best of the results, but not lots of results. However, they may not get results from the best search engines as these are not usually included. Use metasearch engines when you are in a hurry and when you are net sure of the best words to use in your question.

Some examples are:-

Deep” Web Search Engines:-
“Newsgroup” searches, Searching “mailing lists” and searching with “specialty” search engines.

There are billions of web pages made by all kinds of people with information they wish to share or have shared. This information is not all ways in the form of web pages that are “made” but equally, can be. This is the so called “invisible web”.

Rather than try to present this myself I will refer you to the link
which gives you excellent links to this resource. Check it out!

Finally, To Do Searches.
  • Work out on a piece of paper all the key words you want to search for.
  • Use a + sign in front of all the words that you want to find information on.
  • Do not leave a space between the sign+ and the word .. Like  +Australian  +marsupial  +animals.
  • Try to use at least 3 key words.
  • Use double quotation marks [“”] around words to find them exactly as is. Like “australian marsupial animals”
  • If you type them in lower case, you will be given results in BOTH upper and lower case.
  • If you type a * at the end of a word, you will get the results for a word with different endings. Like librar* gives library, libraries, librarian etc.
  • Try to use “Boolean logic” as explained in the Part 1 of this lesson.
If you wish to see a lot more of this go to:-

http://adam.ac.uk/info/boolean.html#boo


I love this site:-
An excellent site for using all kinds of safe search links to searching for kids go to :-

http://www.ivyjoy.com/rayne/kidssearch.htm



 

By Wayne

Created October2001
Updated March 2002

Updated Dec2002,  March 2003


Links checked July 2005

[Taken in part from p 106- 109 “Australian NetGuide” Oct.2001]

Background from http://www.backgroundheaven.co.uk/backgroundframes.htm


Activities For
Search Engines
Search Engines Search Engines1 Search Engines2 Search Engines3 Search Engines4

Index

Wayne
Updated Nov. - Dec. 2004
Feb.  - June  2005