LOGO Searching the Web CHAPTER 2 Eastern Mediterranean University School of Computing and Technology Department of Information Technology ITEC229 Client-Side Internet and Web Programming Prepared by: R. Kansoy

Contents 2.1 Searching the Web 2.2 Search Engines 2.3 Searching Techniques 2

2.1 Searching the Web  If you don't know which site to go to for the information you're looking for you are going to have to search the Web.  The Web is a worldwide resource of information.  A primary reason that people use the Web is to search for specific information, including text, pictures, music, and video.  There are many free services you can use to find information on the Web;  Search Engines, Search Directories, and Meta Search Engine  Some Web sites offer the functionality of both a search engine and a subject directory. 3

2.1 Searching the Web  Search engines constantly visit Web sites in order to catalog Web pages.  Directories are created by humans who assign submitted sites to an appropriate category or categories, such as sports or shopping, and related subcategories.  Meta search engines are search tools that search several search engines at once.  Examples: Search Directory – Yahoo, Search Engine – AltaVista, Meta Search Engine - Mamma.  You can browse through categories, such as arts or sports, to find information that interests you or you can search for a specific word or topic. 4

2.1 Searching the Web 5 Limitations of Internet Research  Information Available  Amount of Time  Quality of Information  There are limitations of using the Internet as a research tool. People often have the misconception that the Internet contains every bit of knowledge...every piece of information ever written, and that all they have to do is type in their subject and they'll be able to pull up exactly what they were looking for.  The Internet doesn't contain every piece of information ever written and probably never will. There have been millions if not billions of books and articles published over time and only a fraction of the information contained within them is on the Internet. The information doesn't magically appear, someone has to put it on the Internet.

2.1 Searching the Web 6  In addition, searching for information on the Internet often takes a great deal of time if you don't know of a site that contains the information.  Depending on your subject and which search engine you use, you may pull up several thousand web pages. And you may look through all of the pages, which could take hours, and even then you may not find what you’re looking for. On the other hand, you can sometimes find a great site with the information you need in only a few minutes.  Also keep in mind that since no one controls the Internet, anyone can put information on it. Some of that information may be useful and some of it be garbage and useless as a source for research.

2.2 Search Engines  A search engine is a program that finds Web sites, Web pages, documments, images, videos, news, maps, and other information related to a specific topic.  A search engine is helpful in locating information for which you do not know an exact Web address or are not seeking a particular Web site.  Are like the index in the back of a book  Search engines require that you enter a word or phrase, called search text or search query, that describes the item you want to find.  Each word in the search text is known as a keyword. 7

2.2 Search Engines  Thousands of search engines are available.  Some search through Web pages for all types of information.  Other search engines can restrict their searches to a specific type of information, such as the following items: 8 Imagespictures, diagrams, and drawings. Videoshome videos, music videos, television programs, and movie clips. Audiomusic, songs, recordings, and sounds. Publicationsnews articles, journals, and books. Mapsmaps of a business or address, or driving directions to a destination. People or Businessesaddresses and telephone numbers. Blogsspecific opinions and ideas of others.

2.2 Search Engines  Pros  Large chunk of publicly available web  Best way to search for specific info on the web  Cons  Too much info!!  Too many irrelevant hits 9

2.2 Search Engines  How do they work?  Crawl the web with “spider” or “bots”  Travels from link to link  Collects information on publicly available pages  Creates an index of all these sites  Matches the search terms you enter to the index  Presents the search with the results list, or “hits” 10

How to Search?  What do you need to know about your topic?  Make a list of all the terms connected with your topic.  Include names, organizations, and phrases.  Make a list of the words that are critical to your search.  Note terms that you don ’ t want to see appear.  Discard the rest. If you are doing serious research on a specific topic, advanced searching is a better option. 2.3 Searching Techniques 11 Well-prepared searches will eliminate useless hits and wasted time. learn how to use a search engine properly to limit the search results to find only the information which is really relevant.

Search Engine Operators Operator Description ExamplesExplanation AND, + Display hits that include specific words art + musicResults have both words art and music — in any order. OR Display hits that include only one word from a list. dog OR puppyResults have either the word dog or puppy. NOT, - Exclude a word from the search results. automobile -convertible Results include automobile but do not include convertible. ( ) Combine hits that include specific words with those that include only one word from a list. Kalamazoo Michigan (pizza OR subs) Results have both words Kalamazoo Michigan and either the word, pizza, or the word, subs. * Substitute characters in place of the asterisk. writer*Results include any word that begins with writer (e.g., writer, writers, writer’s). “ Search for an exact phrase in a certain order. “19th century literature” Results have the exact phrase, 19th century literature. 2.3 Searching Techniques 12

2.3 Searching Techniques 13  Other techniques you can use to improve your searches include the following:  Use specific nouns.  Put the most important terms first in the search text.  List all possible spellings, for example, , .  Before using a search engine, read its Help information.  If the search is unsuccessful with one search engine, try another.

LOGOhttp://sct.emu.edu.tr/it/itec229 Searching the Web END of CHAPTER 2