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UNIT 28: Effective Internet Searching Techniques — Search Features Table of Contents
UNIT 28: Effective Internet Searching Techniques — Search Features
NOT excludes any document containing the term. NOT excludes even a single use of the term in the document. It is most suitably employed to reduce a large number of irrelevant hits when other measures have failed.
Example: "intranet NOT Internet's
When using these operators, remember to capitalize them as shown above.
Exercise
1Write a query that will list web sites on networking and Intranet.
3.1.2 Plus/Minus
Employs [+] before a term to retrieve only the documents containing that term. It is similar to the Boolean AND.
Employs [-] before a term to exclude that term from the search. It is similar to the Boolean NOT.
Do not leave a space between the operator and the term that follows.
Query Example 2: -hcomputer+network—internet
This query gives an enormous number of hits, because each term can be anywhere in the document and is not necessarily related to any other. Nonetheless, because the hits are ranked, the highest-ranking ones should contain all the terms and therefore likely to produce relevant documents.
Use [-] similarly to prohibit the use of a term. This technique is particularly useful when you wish to exclude irrelevant subject matter.
Example 2 will produce a list of hits containing computer and networking and exclude anything web site with internet.
Exercise 2
Write a query that will list web site on Library User Education excluding internet user education.
If you've written it correctly then it should look like this:
Library user education—internet user education 3.1.3 Phrases
Words enclosed within double quote marks denote an exact phrase, or reasonably close to it. It is sometimes similar to the Boolean NEAR. More often, it is treated like a single term and is usually searched as such.
Query Example: "tutorial for beginners"
This example will produce a list of hits containing the phrase "tutorial for beginners" only.
Exercise 3
Write a query that will list web sites containing the phrase "component of the internet"
3.1.4. Stemming [Truncation]
The use of the stem or the main part of a word to search for variations of the word [e.g. the stem
"sing" searches sings, singer, singing and singalong]. Stemming can be automatic, or it may require use of a wild card, symbolized by asterisk [s] to initiate.
Query Example: sing*
To include variations of a keyword, use the wild card symbol [*] after the stem of the word. This broadens a search to retrieve documents that otherwise would be missed.
Query Example: sin*
3.1.5 Case Sensitive
Use lower case for query terms except for proper names.
Treat adjacent capitalized words as a single proper name, e.g. Gbaje Ezra.
Separate proper names from each other with a comma.
Query Example: Gbaje Ezra, Helen Gbaje
However. it is more definite to treat a multiple word name as a phrase, by enclosing it within double quotes.
Example
"Gbaje Sharon Shidinje Oziohu"s
3.2 Query Composition Guides
Despite the differences in the way search engines select, index and retrieve documents, there are common guides that you can use to help compose your query.
Be as specific and complete as you can in selecting your keywords; they are critical to the success of your search.
When possible, employ uncommon or unique terms, for they are less likely to be ignored or filterd. Avoid adjectives and adverbs unless they are part of a phrase; alone they do not convey much meaning.
Arrange your terms in a series from the most general to the most specific; it makes for a more effective search.
Avoid searching for obscure information not likely to be found without use of sophisticated search methods. Once you become familiar with the use of operators, you can move towards the more complex searches.
When you have located a good site about your topic, see- whether it has links to other sites.
Sometimes an important document is found this way. The site may also contain keywords that can improve your query.
In keyword searches, start by working with no more than two or three search tools until you gain some mastery over them. A search tool's help section usually describes its curren t keyword search practices. From these learn how best to compose a query and focus the search.
Use the Refine drop-down lists when offered. They are a simple way to narrow your search.
Avoid m is-spellings, redundant terms and complicated query structu re.
Table I is organized to help identify frequently used operators for our list of preferred search tools.
Table I: Preferred Keyword Search Tools and their Operators
Search Tool Operators Boolean
Marks Plus/Minus Sensitive
Quote Stemming Case
Alta Vista x x x x
Dogpile x x o
Excite x x x o o
Google o x x o o
HotBot x x x x x
Infoseek o x x x x
LookSmart
MetaFind x x
Mamma x x x x
NorthernLight x x x x o
Yahoo x x x x
Table Symbols: [x means supports, [o] means excludes, [s] means a wild card capability.
3.3 Searching by Subject
In comparison to keyword searches, subject searches are rather simple. Subject searches begin with broad subject categories and proceed to subject matter that is increasingly more specific. To use a subject search, follow the search path and at each stop, examine the hits that are provided.
The main advantage of directory searches is that they are of significantly higher quality and relevance than those found through a search engine. This is because subject experts review all documents submitted before they are accepted. Because of this time-consuming effort, directory databases are much smaller than those of search engines.
With some exceptions, directories can take weeks, and sometimes months, to update their database contents. In marked contrast, search engines collect and update web sites automatically, often within one or two days. This is of particular value when being current is important.
Exercise 3
State the advantages of directory searches over keyword search.
3.4 Guides to Effective Searching
Below are guides that can greatly help improve your search results.
If your subject is broad, start with a subject search such as Yahoo, LookSmart or Encyclopedia Britann ica.
If your subject is narrow or specific, use a keyword search such as Ilor, Google, Infoseek, Excite or Snap.
If you are not sure, try Yahoo and take advantage of its keyword option if needed. This option narrows the search to the last subject title, but in a smaller field.
Try a meta engine such as Savvy or Dogpile. Meta engines produce fewer hits usually of higher relevance.
Try a number of different search engines. You will find that the hits produced by the search engines are significantly different, and therefore the chances of your getting the document you want are much improved.
Should your search involve an obscure or difficult-to-find topic, use a search engine having a large database such as Alta Vista, Ilor, Google, HotBot or NorthernLight.
4.0 Conclusion
It can be disconcerting to a user to find that the number of hits obtained can range from none to over a million, and their relevance or usefulness can vary from negligible to considerable.
Too many irrelevant hits are often due to too broad a query, because of an inadequate number of defining terms. Too few hits are often caused by too restrictive a query. However, there are many reasons for poor results.
5.0 Summary
Search engines are used to assist us in searching the internet resources. While each search engine has its own operators. some operators are used in common by a number of search engines. These we studied in this unit. Similarly we looked at how to compose a good search query and how to use directory search to search for information on WWW.
6.0 References and Suggestion for Further Reading
WWWmetrics (http:www.wwwmetrics.com)
Mediametrix (http://www.mediametrix.com/data/thetop.jsp) Greg Notes' Search Engine Showdown
(http://www.notes.com/search/)
Search Tutorial: Guide to Effective Searching of the Internet, revised and updated July 1999, VisualMetrics Corporation,
(http://www.thewebtools.com/tutorial/tutorial.htm) Nua Internet Surveys (http://www.ntia.ie)
lnternetstats (http://www.internetstats.com)
7.0 Tutor-Marked Assignment
Question
Discuss any four keyword search operators and state the advantages and disadvantages of directory search over keyword search