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UNIT 27: Effective Internet Searching Techniques: Search Tools Table of Contents
Page
1.0 Introduction 161
2.0 Objectives 161
3.1 Background to the Study 161
3.2 Search Tools and Methods 161
3.3 Search Tools 162
3.3.1 Types of Search Tools 162
4.0 Conclusion 164
5.0 Summary
164
6.0 References and Suggestion for Further Reading 164
7.0 Tutor-Marked Assignment 164
1.0 Introduction
Conducting a search can be time consuming and frustrating for the non-expert. This is not surprising given the enormous amount of information available on the World Wide Web and the different ways it is stored and retrieved. The search process is made all the more difficult because of the large number of search tools, their differing information content and the lack of industry standards. In this unit and subsequent units on Effective Internet Search, we will be looking at how you can effectively search the internet for information.
2.0 Objectives
At the end of this unit we will be able to:
Explain why it is difficult to locate information from the WWW;
Identify the various search tools;
State the advantage's and disadvantages of each search tool;
List some search tools w eb sites.
3.1 Background to the Study
Before we can develop effective searching techniques for the Internet, we need to review some pertinent facts about the Internet itself. There are currently over 11 million sites on the World Wide Web. also known as WWW and are over 1 billion pages on the WWW in computers all over the world. These specialized computers are linked to form part of a worldwide communication system called the Internet. When you conduct a search, you direct your computer's browser to go to Web sites where documents are stored and retrieve the requestd information for display on your screen.
Millions of new Web pages are being added each week, some existing pages are being updated or altered in some significant ways, and some pages are being removed. Because the Web is so large, it is not feasible for any search engine to search the entire Web. Instead, most search engines generate a database of information derived from Web sites and pages. These databases cannot include all Web pages: in fact, the largest databases (probably Alta Vista and Northern Light) contain intbrmation on about 250 million Web pages. Other search engines claim to use a quality rather than quantity approach and limit the size of their databases.
Most Internet search engines allow anyone to submit Web pages (there's usually a link labelled 'submit/add/suggest a page/site/URL'). Once the page is submitted, the search engine sends out a computer-robot programme called a crawler (spiders, Web; get it). The crawler gathers the information and returns it to the database.
Web crawlers also go out on their own looking for new sites and checking up on old ones. As a result, it's very possible that your site might be added to an index even though you've taken no action.
3.2 Search Tools and Methods
A search tool is a computer programme that performs searches. A search method is the way a search tool requests and retrieves information from its Web site.
A search begins at a selected search tool's Web site, reached by means of its address or URL.
Each tool's Web site comprises a store of information called a database. This database has links to other databases at other Web sites, and the other Web sites have links to still other Web sites, and so on. Thus, each search tool has extended search capabiliti es by means of a worldwide system of links.
Exercise 1
State 3 reasons why locating an information from the web is difficult.
3.3 Search Tools
A search tool employs a computer programme to access Web sites and retrieve information. Each search tool is owned by a single entity, such as person, company or organisation, which operates it from a master computer. When you use a search tool, your request travels to the tool's Web site.
There, it conducts a search of its database and directs the response back to your computer.
3.3.1 Types of Search Tools
There are essentially four types of search tools, each of which has its own search method. The following describe these search tools and then suggest exercises for achieving a familiarity with their use.
1. A directory search tool searches for information by subject matter. It is a hierarchical search that starts with a general subject heading and follows with a succession of increasingly more specific sub-headings. The search method it employs is known as a subject search. Choose a subject search when you want general information on a subject or topic. Often, you can find links in the references provided that will lead to specific information you want.
Advantage: It is easy to use. Also, information placed in its database is reviewed and indexed first by skilled persons to ensure its value.
Disadvantage: Because directory reviews and indexing is so time consuming, the number of reviews are limited. Thus, directory databases are comparatively small and their updating frequency is relatively low. Also, descriptive information about each site is limited and general.
2. A search engine tool searches for information through use of keywords and responds with a i list of references or hits. The search method it employs is known as a keyword search. If you w
wish to obtain specific information, choose a keyword search, since its extensive database is likely to contain the information sought.
• Advantage: Its information content or database is substantially larger and more current than that of a directory search tool.
Disadvantage: Not very exacting in the way it indexes and retrieves information in its database, which makes finding relevant documents more difficult.
3 A directory with search engine uses both the subject and keyword search methods interactively as described above. In the directory search part, the search follows the directory path through increasingly more specific subject matter. At each stop along the path, a search engine option is provided to enable the searcher to convert to a keyword search. The subject and keyword search is thus said to be coordinated. The further down the path the keyword search is made, the narrower is the search field and the fewer and more relevant the hits. You can use this search tool when you are uncertain whether a subject or keyword search will provide the best results.
Advantage: Ability to narrow the search field to obtain better results.
Di s a d v an t a g es : This search method may not succeed for difficult searches.
Some search tools use search engine and directory searches independently. They are said to be non-coordinated.
4. A multi-engine search tool (sometimes called a meta -search) utilizes a number of search engines in parallel. The search is conducted via keywords employing commonly used operators or plain language. It then lists the hits either by search engine employed or by integrating the
results into a single listing. The search method it employs is known as a meta search. You can use multi-engine to speed up the search process and to avoid redundant hits.
Advantage: Tolerant of imprecise search questions and provides fewer hits of likely greater relevance.
Disadvantage: Not as effective as a search engine for difficult searches.
Of the hundreds of search tools available, listed below are examples of Search tools and their URL.
Table 1: Search Tools
Search Tool Category 'Websight
Encyclopaedia Britannica Directory [Subject Search]
Look Smart Directory [Subject Search] www.looksinart.com
Yahoo* Directory [Subject Search] www.yahoo.com
Alta Vista Search Engine Keyword Search www.altavista.com
Google Search Engine Keyword Search www.google.com
Excite Search Engine Keyword Search www.Excite.com
llor Search Engine Keyword Search WWW. i I or. co m
Hotbot Search Engine Keyword Search www.hotbot.com
lnfoseek Search Engine Keyword Search www.infosee.com
Northern Light Search Engine Keyword Search www.northernlight.com
Mamma Multi-Engine Meta Search www.mamma.com
Dogpile Multi-Engine Meta Search wv,Av.dogpi le
Metacrawler Multi-Engine Meta Search www.metacrawler
SavyySearch Multi-Engine Meta Search www.sayvysearch.com
Activity 2
Conduct the following searches and write down the differences between the result produced by the search tool.
a . D i r e c t o r y [ S u b j e c t S e a r c h ]
Type http://www.yaltoo.com in the location box of your Internet Browser [e.g. Netscape Navigator or MS Explorer]. Press Enter. The Yahoo! Home Page is displayed. From the subject list provided, choose and click a category of your interest to follow. Choose titles that are increasingly more specific until there are no more options of interest offered. Scroll through the references or hits, and click a hit that interests you to get an abstract or title of the reference.
b. Search Engine (Keyword Search).
Type http://www.ilor.com in the location box of your Internet Browser and press Enter to access the Home Page. Using keywords, type your question or query into the location box.
Click Find. Examine the hits of interest and click one to access the reference.
4.0 Conclusion
The dynamic nature of the Web is one of its true strengths, but it is also problematic when it comes time to finding something. To assist us, several search tools are available and new ones are coming online on a regular basis. Each of these search tools has a unique way of doing some things but there are some things they have in common. Hence in this unit we were able to look at some few search tools and how they work as well as their advantages and disadvantages.
5.0 Summary
There are four basic types of search services: subject directories that classify websites, search engines that perform keyword searches within websites, multi-engine search tool (sometimes called a meta-search) that utilizes a number of search engines in parallel and a directory with search engine that uses both the subject and keyword search methods interactively.
6.0 References and Suggestion for Further Reading
WWWmetrics (http://wvvw.wwwmetrics.com)
Mediametrix (http://www.mediametrix.com/data/thetop.jsp) Greg Notes' Search Engine Showdown
http://www.notess.com/search/)
Search Tutorial: Guide to Effective Searching of the Internet, revised and update July 1999, VisualMetrics Corporation, (http://www.thewebtools.comAutorialAutorial.htm)
Nua Internet Surveys (http://www.nua.ie) Internetstats (http://www.intemetstats.com)
7.0 Tutor-Marked Assignment
Question
What are the main categories of the search tool? Also state the advantage and disadvantage of each search tool.