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Searching the Internet |
Searching
As you are aware, the Internet is a huge place and finding what you want would
be impossible without some assistance. Unlike a library where all material is
catalogued and can be accessed directly through the catalogue, the World Wide
Web has no catalogue system. However, more than 2500 special tools have been
created to assist you in locating information. These tools can generally be
classified as either 'search engines' or 'directories'.
Search engines consist of three parts:
When you use a search engine, you are NOT searching the entire Internet. You are only searching previously created database entries of that search engine. This index represents only a small a portion of the Web material.
Because search engines index key words contained in documents, it is possible that millions of documents may be listed in response to a search for a key word. Searching techniques have been developed to help sift through the millions of entries to reduce the results to a manageable number of pertinent documents. However, because no two search engines are the same, the results will be different and the search options may vary.
The better search engine databases only index approximately 16% of all material available on the WWW, and because of the rapid growth of the Internet, this percentage is falling . This makes it important to use more that just one search engine in your search.
Because the Internet is constantly changing, search engines must spend time keeping their database up to date, i.e. adding new pages and removing pages that no longer exist. Pages that are not listed reduce the possibility of the end user locating the required information. Pages that no longer exist but are still listed by the search engine, lead to broken links .(Which waste end-user time and create much frustration)
| Search engines |
| www.google.com |
| www.au.altavista.com |
| www.anzwers.com.au |
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An example search engine is Google.
Like other search engines, Google has:
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Unlike search engines, subject directories are created and maintained by human
editors. The editor views sites and determines its placement in a subject classification.
Once classified, certain keywords associated with those sites can be used for
searching the directory's database to find Web sites of interest. Once the number
of listings in a category exceed approximately on thousand, the category is
divided into sub categories.
Directories may be of a general nature or they may specialise in a subject area,
such as business, engineering, health or humanities.
To use a directory, select a topic and start clicking on sub topics until you come to a page of interest. You may conduct a search within a category. Because humans have compiled directories, they tend to deliver higher quality and fewer results than search engines.
Use a directory to find information on topics such as AIDS (HIV). Searching within the subject of Medicine for "AIDS" will eliminate responses to non-health topics e.g. teaching aids!
| Directories |  |
| www.yahoo.com | |
| www.academicinfo.net/ | |
| www.csu.edu.au/education/library.html | |
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Metasearch engines do not crawl the web compiling their own searchable databases.
Instead, they search the databases of multiple sets of individual directories
and search engines simultaneously, from a single site and using the same interface.
Metasearchers provide a quick way of finding out which engines are retrieving
the best results for you in your search.
Metasearch engines do not return all the results retrieved from the individual
engines they search. However, the searches they do return are drawn from the
top of search engine lists, and therefore tend to be more relevant.
On search engines and directories
The distinction between search engines and directories is becoming blurred as
search engines cluster information into directory like structure.
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Meta search engines |
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Search engines are best at finding unique keywords, phrases, quotes, and information buried in the full-text of web pages. Because they index word by word, search engines are also useful in retrieving tons of documents. If you want a wide range of responses to specific queries, use a search engine."
"Subject directories are best for browsing and for searches of a more general nature. They are good sources for information on popular topics, organizations, commercial sites and products. When you'd like to see what kind of information is available on the web in a particular field or area of interest, go to a directory and browse through the subject categories."
Use a metasearch tool "if you have a reasonably
simple topic and you wish to get a quick result from many search engines and
subject directories simultaneously." Use metasearchers when you are in
a hurry. Metasearch engines are useful in obtaining a quick overview on a subject
and/or unique term. Use metasearchers when you are conducting a relatively simple
search and also when you are not having any luck pulling up documents in your
search.
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Use nouns
Because nouns describe tangible things, use them in your
query - use several - up to about six. Put the most important noun first.
Put a + sign in front of each noun to ensure that it is contained on the page.
Example:
+hybrid +electric +gas +vehicles
See Boolean Searching
Use stemming
"Many terms you want to search on may appear in singular or plural format.
As a time saving measure, some search engines allow you to search for both the
singular and plural forms simultaneously. This is known as truncation or the
use of "wildcards".
When searching AltaVista, Hotbot or Northern Light you can use * at the end
of a word to search for plurals or alternative endings of words (e.g. wine*
will mean a search for wine, wines; educat* will mean a search for educate,
educates, education, educational, etc.).
Use the right level
Try to be specific when describing an object or concept. For example, referring
to the diagram shown below, when searching for information relating to a particular
type of bird, it is best to use a term from level six or seven than from level
four.
The following results are quoted in http://www.brightplanet.com/deepcontent/tutorials/search/part3.asp
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Number of results |
Comment |
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bird*results falcon* peregrine falcon* |
1,834,510 340,707 14,510 |
far too many
still a lot manageable |
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Use synonyms
Use a thesaurus to find synonyms to try in your search. Use botanical names
and common names for plants and animals. See
Boolean Searching
Phrase searching is very useful if you want terms to appear next to each other
in your result. If words naturally belong together, include them in double quotation
marks.
Example: "search engine tutorial" "endangered species"
Phrase searching is a very powerful tool, remember to use it!
Capitalisation
Some search engines recognise capitalisation. To illustrate this, if you are
looking for information on Mr. Bill Gates and don't want information on gates
that open and close, using capitalisation will narrow your search.
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Boolean Searching
AND
Terms on both sides of this operator must be present somewhere in the document
in order to be scored as a result. This is the most used of all the Boolean
operators.
You are looking for wineries in Western Australia (i.e. both concepts must appear
in your result), you would use the terminology
wineries AND "Western Australia" (notice the use of phrase
searching)
OR
Terms on EITHER side of this operator are sufficient to be scored as a result.
Use to search for synonyms. E.g. (feline OR cat)
You want information on either wine or beer (i.e. either of the terms can appear
in your result). The Boolean language for this is:
wine OR beer
NOT
The term on the right of the operator must not be found in the document
If you are looking for information on wine but don't want information about
cabernet sauvignon (i.e. you want one term but not the other), the Boolean terminology
would be
wine NOT "cabernet sauvignon"
NEAR
Similar to AND, only both terms have to be within a specified word distance
from one another in order to be scored as a result
BEFORE
Similar to NEAR, only the first (left-hand) term before this operator has to
occur within a specified word distance BEFORE the term on the right side of
this operator in order for the source document to be scored as a result
AFTER
Similar to NEAR, only the first (left-hand) term before this operator has to
occur within a specified word distance AFTER the term on the right side of this
operator in order for the source document to be scored as a result
+ and -
Implied Boolean operators use the plus (+) and minus (-) symbols in place of
the full Boolean operators, AND and NOT. Typing a (+) or (-) sign in
front of a word will force the inclusion or exclusion of that word in the search
statement.
EXAMPLE: +bulimia -anorexia
Will return pages that include the word bulimia but do not contain the word
anorexia.
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After conducting your search engine query, you have opened a page that was listed in the results. The question is, does this page contain the word(s) you were looking for? To find the answer to this question, you need to search the page.
The method used to find a set of characters on a web page is very similar in Explorer and Netscape
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Copyright © Dubbo College 2003 - Bryan Jeffress HTTL
Last updated July 2003
