Module 1: What's out there?

More advanced search techniques

Meta-search engines and clustering search engines
M1 Task 9 - Using meta-search engines
Boolean searching
More information

Meta-search engines and clustering 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 effort) it doesn't always work that way. There are differences, for instance, in the way each search engine interprets the words and symbols entered.

Meta-search engines are often worth trying, since no one search engine covers all of the Internet websites in existence. To avoid problems of syntax it is sometimes better just to type in a list of keywords.

Clustering search engines sort the search results into folders by categories. This is often very useful for narrowing your search or for looking at a subject from a specific angle. Vivisimo is a meta-search engine that uses fully automated document clustering to organise results in a hierarchy. The concept clusters are unique to each search.

Some examples of meta-search engines are:

ProFusion
http://www.profusion.com

MetaCrawler
http://www.metacrawler.com

Macintosh users with System 8.1+ also have access to the built-in meta-search engine called Sherlock.

An example of a clustering search engine is:

Vivisimo
http://vivisimo.com/

Boolean searching

Most search engines have advanced modes in which you use Boolean logic (named after mathematician George Boole) 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.

You have already used some Boolean logic in your searches. The plus sign '+' is usually equivalent to AND, the minus sign '-' is equivalent to NOT. In most search engines, listing of words without symbols equals AND. See Task 7 in this module for a discussion of these devices.

Some search engines use a drop-down menu with terms like All of these words or Any of these words or None of these words. These are substitutes for the logical operators AND, OR and NOT. Visit the University at Albany site Boolean Searching on the Internet (http://library.albany.edu/internet/boolean.html) to find out more.

Take a look at AltaVista's advanced search window by clicking on Advanced Search (http://www.altavista.com). Find out how to use this effectively by visiting AltaVista's advanced search help page. Click on Help and then Advanced Search.

If you are interested in advanced searching and Boolean logic, there are several suitable tutorials available (search for 'Boolean tutorial'). 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

Some search engines can search for other formats on the web, such as images or audio files. Google, AltaVista and AllTheWeb have image search features. This can be particularly useful if you wish to exclude references that are only text-based.

In some search engines you also have a choice of language. You may wish to limit this to English for text, but if you are searching for images, you may prefer to use the All option to widen the available images to include non-Western, European and Asian art.

If you are looking for information specific to Australia, check the search engine you are using for an Australian option. Yahoo! Australia & New Zealand (http://au.yahoo.com/), AltaVista (http://au.altavista.com) and ninemsn (http://search.ninemsn.com.au/) are all local versions of major search engines. There are also other search engines like Anzwers (http://www.anzwers.com.au/) and Web Wombat (http://www.webwombat.com.au/) that search Australian websites.

There are search engines for children, such as, Yahooligans! (http://www.yahooligans.com/) and Ask Jeeves for Kids (http://www.ajkids.com/) which pre-filter potentially objectionable sites.

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 by Joe Barker, Finding Information on the Internet: A Tutorial (http://www.lib.berkeley.edu/). Under Using the Libraries, click on Starting your Research. You will find Finding Information on the Internet: A Tutorial under How to Use Internet Resources.

A shorter but very practical guide by Debbie Flanagan is Web Search Strategies (http://www.learnwebskills.com/search/main.html).