Lesson 12 — The Internet and Research Unit 3 — Advanced Computer Concepts Lesson 12 — The Internet and Research

Lesson 12 – The Internet and Research Objectives List some reasons for searching the Internet. Describe different search approaches. Define a search engine. Explain how search engines work. Describe how search engines search. Lesson 12 – The Internet and Research

Objectives (continued) Identify some of the more popular search engines. List some of the specialty search engines. Describe the subject directory search approach. Describe some search tips and tricks. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Internet Search Tools There are two basic types of Internet search tools: Search engines Perform searches based on keywords Subject directories Search by specialized topics What is the difference between them? Search engines are automated. Directories are assembled by people. Lesson 12 – The Internet and Research

Why Search the Internet? Some reasons that people search the Internet include Research for school assignments. Looking for medical and scientific information. Travel information and accommodations. Shopping for goods and services. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research What Is a Search Engine? Search engines are programs that allow you to search for information. There are hundreds of search engines on the Internet. Search engines allow keyword searching. Some support concept-based searching. Some support stemming. The list of results returned from your search are called hits. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Keyword Searches Keyword searches look for specific words within a Web page. Many search engines use meta tags to build their search index. Meta tags are HTML tags in a Web page that do not display, but can be used to define page content. Search engines also use significant words to build their index. Significant words may be words mentioned near the beginning of a page or repeated frequently throughout the page. Some search engines claim to index all words in a Web page. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Keyword Search Steps To search using keywords: Connect to the Internet and go to a search engine site. Enter your keywords in the search box. Many search engines allow you to enter a phrase or a sentence. The search engine examines its internal database index looking for your words. The search engine returns a list of hyperlinks (hits) to Web sites containing your words. Click a hyperlink to go to that site. If you get no hits on your search, revise your keywords and try again. Lesson 12 – The Internet and Research

Search Engine Components Search Engines usually have three main components: The search engine program that does the search of its database. A spider or crawler that looks for the information in the database. The index which is built from information returned by the spider. Lesson 12 – The Internet and Research

Check the Relevance Rating Search engines usually provide a relevance rating percentage for each hit. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Major Search Engines Although there are hundreds, these are some of the most well known: Lycos – www.lycos.com Yahoo! – www.yahoo.com AltaVista – www.altavista.com Google – www.google.com Infoseek – www.infoseek.com Excite – www.excite.com WebCrawler – www.webcrawler.com Lesson 12 – The Internet and Research

Specialty Search Engines These are also called category-oriented search engines. They are commonly used for Locating people. Finding shareware and freeware. Shopping. Sports-related information. Career planning. Lesson 12 – The Internet and Research

A Specialty Search Web Site This figure shows the Beaucoup Web site page. Note the various categories of informa-tion available. Clicking a sub-category will bring up a new page of categories until you find the exact topic you are searching for. Lesson 12 – The Internet and Research

Subject Directory Searching Subject experts personally examine Web sites and add the URL to a search engine if it meets standards. Subject directories are organized by subject categories. Each category has a collection of links to Internet resources. The resources are arranged by subject and displayed in menus. You start at the top of a category and drill down from a generic start to a specific topic. Lesson 12 – The Internet and Research

A Subject Directory Site This figure shows the Encyclopedia Britan-nica Web site. Note the subject list on the left side of the screen. Lesson 12 – The Internet and Research

Advantages of Subject Directory Searches They usually provide a more guided approach than keyword searches. They are easy to use. You are not searching the entire Web. The linked sites have been handpicked and evaluated. Most links include a description. They produce better quality hits on searches for common items. Lesson 12 – The Internet and Research

Popular Subject Search Sites Encyclopedia Britannica – www.britannica.com The Librarians Index – www.lii.com Yahoo – www.yahoo.com Galaxy – www.galaxy.com Lesson 12 – The Internet and Research

Tools and Techniques for Searching Some commonly used techniques are Phrase searching Search engine math Boolean searching Wildcard searching Title searching Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Phrase Searching This is used to search for words that must appear next to each other. Phrases must be enclosed in double quotation marks. For example: “books on the Civil War” Only sites with the exact phrase will be returned as hits. You should capitalize proper nouns. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Search Engine Math Use math symbols to enter formulas or to filter out unwanted listings. A plus sign (+) before a word means it must appear. A minus sign (-) before a word means it should not appear. For example, to search for sites that contain both cookies and recipes, enter: +cookies+recipes to exclude sites that have coconut cookie recipes, enter: +cookies+recipes-coconut Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Boolean Searching Boolean logic is similar to search engine math, but is more powerful. Boolean logic consists of three operators: AND: Search for sites that include Word A AND Word B. NOT: Search for sites the include Word A but NOT Word B. OR: Search for sites that include Word A OR Word B. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Advanced Search Forms This figure shows the advanced search form for the HotBot Web site. It is designed to assist you in performing math and Boolean logic-oriented searches by setting text box options. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Wildcard Searching Wildcard searching allows you to search for words that you may not know the spelling of or to search for plurals or variations of a word. The wildcard character (*) lets you search for any word that has the characters before or after the wildcard character. For example, to search for the element potassium without knowing how it is spelled, enter: PO* or po*ium Not all search engines support wildcard searches. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Title Searching Web pages usually contain an HTML <Title> tag. The text in that tag is displayed in a Web browser title bar when the page is loaded. Several (but not all) search engines allow you to search for specific Web page titles. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Related Searching Some search engines have a related search feature. The search engine will return hits based on your search criteria and may also display a list of other sites that have information related to your search criteria. This can greatly improve the odds of finding the information that you want. Note: Some sites call this feature similar pages or more pages like this. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Summary Two basic tools you can use for finding information are search engines and directories. People assemble directories, and search engines are automated. A search engine is a software program. Most search engines support keyword searches. Concept-based searching occurs when the search engine returns hits that relate to keywords. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Summary (continued) Stemming relates to the search engine finding variations of the word. Meta tags are special tags embedded in a Web page; many search engines use the tags to create their index. Keywords describe the information that you are trying to locate. Search engines contain a database of organized information. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Summary (continued) Some search engines use natural language. A search engine has three main parts: the search engine software, a robot that searches for keywords, and an index. Stop words such as www, but, or, and so forth are not indexed by many search engines. The URL is the same as the Web site address. A relevance rating percentage indicates how close a site matches keywords. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Summary (continued) A search engine uses an algorithm to index Web sites. Specialized search engines focus on a particular topic. Multimedia search engines focus on video, animation, graphics, and music. Subject directories are organized by subject categories. Subject experts check the Web sites that are part of the subject directory’s database. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Summary (continued) Use double quotation marks around a set of words for phrase searching. Use the plus and minus sign for inclusion and exclusion of words with a search. Boolean searches use the three logical operators OR, AND, and NOT. The * symbol is used for wildcard searching. Lesson 12 – The Internet and Research

Lesson 12 – The Internet and Research Summary (continued) Some search engines support title searching. A related search is a preprogrammed question suggested by the search engine. No single organization indexes the entire Internet. Lesson 12 – The Internet and Research