Asia EdNet Tutorial - Module 1
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What's out there and how do you find it? |
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More advanced search techniques 
Meta-search engines
Meta-search engines do not actually perform searches themselves. Instead, they send the search expressions to a range of search engines so that a number of searches are performed simultaneously. Although this sounds like a very good idea (because it seems as if you get more searches for your money) it doesn't always work that way. There are differences, for instance, in the way each search engine interprets the words and symbols entered.
However, meta-search engines are often worth trying since no one search engine covers even half of the Internet websites in existence. To avoid problems of syntax it is sometimes better just to type in a list of key words.
Some examples of meta-search engines are:
MetaCrawler
http://www.metacrawler.com/
Dogpile
http://www.dogpile.com/
Macintosh users with System 8.1+ also have access to the built-in meta-search engine called 'Sherlock'.
Task 10 - Meta-search engines
Try one or more of your previous searches using Dogpile (http://www.dogpile.com/) and compare the results with those obtained by using AltaVista only.
Dogpile is said to support the use of the symbols *, +, -, and " ", 'translating' them as required when passing them to its search engines. Try your search with and without these devices.
Boolean searching
As previously noted, most search engines have 'advanced' modes in which you use Boolean logic to construct a search. Boolean searching is a way of combining keywords in such a way as to produce more accurate results. The Boolean operators commonly used include AND, OR and NOT, among others.
As it happens, you have actually already used some Boolean logic in your searches - the + sign is usually equivalent to 'AND', the - sign equivalent to 'NOT' and simply listing the keywords without any other devices is usually equivalent to 'OR'. See Task 8 in this module for a discussion of these devices.
Here is Google's advanced search window (http://www.google.com.au/advanced_search). You can visit Google's advanced search help page (http://www.google.com.au/help/refinesearch.html) to find out how to use this effectively.
If you are interested in advanced searching and Boolean logic, there are several suitable tutorials available. It is well worth working through one of these if you are intending to do complex and extensive searching but it may take considerable time! Be aware that there is no consensus about the 'best' way to search. Looking at these tutorials will simply give you other opinions about how to go about it.
More information
The following are good general resources covering many aspects of searching the Internet, including advanced search techniques.
The University of California at Berkeley has an extensive and detailed tutorial, Finding Information on the Internet: A tutorial (http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/FindInfo.html).
A shorter but very practical guide by Debbie Flanagan is Web Search Strategies (http://home.sprintmail.com/~debflanagan/main.html).
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