Unit 1—Computer Basics Lesson 3 The Internet and Research

Computer Concepts BASICS - 2 Objectives List some reasons for searching the Internet. Describe different search approaches. Define a search engine. Explain how search engines work. Identify some of the more popular search engines.

Computer Concepts BASICS - 3 Objectives (cont.) List some of the specialty search engines. Describe some search tips and tricks. Describe the subject directory search approach. Describe the invisible Web.

Computer Concepts BASICS - 4 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.

Computer Concepts BASICS - 5 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.

Computer Concepts BASICS - 6 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 that is built from information returned by the spider

Computer Concepts BASICS - 7 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.

Computer Concepts BASICS - 8 Keyword Searches (cont.) 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.

Computer Concepts BASICS - 9 Major Search Engines Although there are hundreds, these are some of the more well known search engines: Google at google.com Google Microsoft at bing.com Yahoo at yahoo.com Ask Jeeves at ask.com

Computer Concepts BASICS - 10 Specialty Search Engines These also are called category-oriented search engines. They are commonly used for Locating people (whitepages.com, imdb.com) Academic research (eric.ed.gov) Shopping (bizrate.com, froogle.com) Travel (travelocity.com, expedia.com) Medical information (webmd.com)

Computer Concepts BASICS - 11 Tools and Techniques for Searching Some commonly used techniques Phrase searching Search engine math Boolean searching Wildcard searching Title searching

Computer Concepts BASICS - 12 Phrase Searching This is used to search for words that must appear next to each other. Phrases must be enclosed in double quotation marks. “Books on the Civil War” Only sites with the exact phrase will be returned as hits. You should capitalize proper nouns.

Computer Concepts BASICS - 13 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.

Computer Concepts BASICS - 14 Search Engine Math (cont.) Examples of search engine math 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

Computer Concepts BASICS - 15 Boolean Searching 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. Can be accessed from Advanced SearchAdvanced Search

Computer Concepts BASICS - 16 Wildcard Searching Wildcard searching allows you to search for words for which you may not know the spelling 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.

Computer Concepts BASICS - 17 Wildcard Searching (cont.) Wildcard search 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.

Computer Concepts BASICS - 18 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.

Computer Concepts BASICS - 19 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. You start at the top of a category and drill down from a generic start to a specific topic.

Computer Concepts BASICS - 20 Popular Subject Search Sites About: about.comabout.com The Librarians Index: Yahoo: Galaxy:

Computer Concepts BASICS - 21 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.

Computer Concepts BASICS - 22 The Invisible Web Also known as the “deep Web” Indexes searchable databases, such as password-protected library databases Resources

Computer Concepts BASICS - 23 Summary Search engines and directories are two basic tools that you can use to find information on the Web. People assemble directories; search engines are automated. A search engine is a software program. Most search engines support keyword searches.

Computer Concepts BASICS - 24 Summary (cont.) Concept-based searching occurs when the search engine returns hits that relate to keywords. Stemming relates to the search engine’s capability to find variations of a word. Meta tags are special tags embedded in a Web page; many search engines use the tags to create their indexes.

Computer Concepts BASICS - 25 Summary (cont.) Keywords describe the information you are trying to locate. Search engines contain a database of organized information. Some search engines use natural language. A search engine has three main parts: the search engine software, a spider that searches for keywords, and an index.

Computer Concepts BASICS - 26 Summary (cont.) Stop words, such as www, but, and or, are not indexed by many search engines. 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.

Computer Concepts BASICS - 27 Summary (cont.) Subject directories are organized by subject categories. Subject experts check the Web sites that are part of a subject directory’s database. Use double quotation marks around a set of words for phrase searching. Use the plus and minus signs for inclusion and exclusion of words within a search.

Computer Concepts BASICS - 28 Summary (cont.) Boolean searching uses the three logical operators OR, AND, and NOT. The * symbol is used for wildcard searching. No single organization indexes the entire Internet.