logging in or signing up HyperResearch04pp Boyce Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 78 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: December 13, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Best Web Directories and Search Engines : Best Web Directories and Search Engines Order Out of Chaos on the World Wide WebDifferent Ways to Search on the Web: Different Ways to Search on the Web Input URLs, surf links Subject directories Search engines Metasearch enginesWeb Directories: Web Directories Small, selective databases Created by humans not machines Editors select and place sites into categories for easy retrieval User browses categories and links to sites How Directories Work: How Directories Work Browse subject categories Funnel: from categories to web sites Health Yahoo! LookSmart Fitness Open Directory Yoga Most popular sites yogabasics http://www.yogabasics.com/Directory Search Boxes: Directory Search Boxes Use when subject categories don’t match your topic: winemaking in Slovenia Be aware a directory first searches its own select database may automatically default to a search engine if it finds little in its own database LookSmart defaults to WiseNut Open Directory defaults to GoogleWhy Use Directories?: Why Use Directories? Identify major and quality sites Get overview, general information on topic Enjoy serendipity in discovery as you manipulate a small, focused file Small, Selective Directories: Small, Selective Directories Librarian’s Index to the Internet 14,000+ Informine 120,000+ Academic Info 25,000+ WWW Virtual Library Large, Less Selective Directories : Large, Less Selective Directories Yahoo!: 3,000,000+ Open Directory: 3,800,000+ LookSmart: 2,500,000+ HyperResearch Guide Web Search Engines: Web Search EnginesWhat Are Search Engines?: What Are Search Engines? Spiders, crawlers Visits, reads web page, follows its links Index, catalog Giant book containing web page spider finds Spiders update pages and add to index Search interface Sifts through index to find matches to words in searchbox Ranks pages for relevancySearch Engines are Same and Different: Search Engines are Same and Different Search engines are the same Consist of crawlers, index, interface Search engines are different Low overlap of database contents 50% of pages in one not found in another Pages for inclusion found internally, by following links, or by submission Remember: Google doesn’t know it all!How Search Engines Work: How Search Engines Work Spider “capture” web pages Web pages build index, database Interface finds words in database Engine ranks, describes results How engines and directories differ Spiders Capture Web Pages: Spiders Capture Web Pages Spider “reads” database text into index Google ~ 100K, Yahoo ~ 500K Spider follows page links, reads new pages into index Spider returns to sites (every month or two) and look for changes Dead sites removed, current sites updated New sites added (through new links found or submitted by others) Web Pages Build Database: Web Pages Build Database Current web size: over 15 billion pages Each database has different pages No engine’s database covers it all Google ~ 29% (4.3 billion+) Yahoo! ~ 20% (3 million+) HotBot ~ 20% (3 billion+) Teoma ~ 13% (2 billion) As pages are updated, nature of database changesInterface Finds Words in Database: Interface Finds Words in Database Provides keyword search box Offers search options to affect results Assumes AND between words: Iraq WMD Uses “quotes” for PHRASE searches: “Cold War” Allows FIELD searching : ti:Russian mafia url:russianmafia Offers Simple and Advanced Search Teoma Engine Ranks, Describes Results: Engine Ranks, Describes Results How “relevance” is determined Location and frequency of search words Title tag, near top of page of indexed text Site popularity ~ how many “clicks” a site get Link popularity ~ how often others link to site Subject popularity ~ link popularity within subject communities (Teoma) Results described, keywords highlightedHow Engines and Directories Differ: How Engines and Directories Differ Computers vs people Spiders select documents Editors select documents Quantity vs quality Engines large, non-judgmental Directories small, want “best” “most important” Technology vs human factor Software ranks items Editors organize pages into subject, categoriesWhy Use Search Engines?: Why Use Search Engines? You need specific rather than general information What role did the Romans play in developing a wine culture in Slovenia? You need a large, comprehensive database in contrast to a directory Note: remember, search engine crawlers grab anything and everything; selectivity depends on you and the engine’s ranking system Top Search Engines: Top Search Engines Google 4.3 billion+ Yahoo (Inktomi) 3 billion+ HotBot (Inktomi) 3 billion+ Teoma 2 billion+ HyperResearch GuideMetasearch Engines: Metasearch Engines Metasearch Engines: Metasearch Engines Technologies that search several search engines at the same timePros: Pros Increase results when one search engine produces little Save time by searching several engines at once Show results of several engines on one pageCons: Cons Retrieve too many hits Retrieve less relevant results Cannot read individual search syntax well Cannot tell if syntax requires terms in upper. lower case (OR~or~and~AND? Cannot tell if title, URL searching allowed, etc. Contain mix of major search engines, not allTop Metasearch Engines: Top Metasearch Engines Vivisimo Clusters results into subject folders Dogpile Refines results, covers major engines Ez2find Includes most major enginesA Few Words About the Web and Search Engines: A Few Words About the Web and Search Engines What’s In Search Engines?: What’s In Search Engines? Business, commercial information Organizational publications Government resources Some magazine, newspaper articles Some scholarly information Teaching materials, unpublished articles Books, articles whose copyright expiredWhat’s Not in Search Engines: What’s Not in Search Engines Most books and periodical articles Current, past research, fiction, non-fiction Reference materials Best current encyclopedias, handbooks, business advisory services, etc. Bulk of human knowledge and research Where can some of this information be found? In libraries in print or via subscription databases available in libraries, institutions, organizations Widening Google and Yahoo’s Eyes for Scholarship: Widening Google and Yahoo’s Eyes for Scholarship OAIster University of Michigan and Yahoo project 3,000,000 scholarly documents 277 institutions involved Open WorldCat OCLC and Google project 2,000,000 books in Google index Open access to 54 million books is goalSearch Tips: Search Tips Check “advanced” search and options Learn about AND, OR, ANY, ALL, PHRASE Know how to search in titles, URLs Spell it right Switch engines, get different results Keep up to date about search engines Newspapers and magazines Library web sitesLearn to Evaluate Web Sites: Learn to Evaluate Web Sites Accuracy Is information reliable? Where is it from? What does URL tell you? (com, .org, .gov, .edu)? Authority Author’s credentials? Address, email given? Content and Currency Purpose of site: inform, sell, propagandize? Date? Documentation Are sources given, footnotes? Are other links given? Find and Evaluate: Find and Evaluate Use Google and find Website titled: The Burmese Mountain Dog Evaluate this site for Accuracy Authority Content and Currency Documentation Is it a trustworthy Web site? You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
HyperResearch04pp Boyce Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 78 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: December 13, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Best Web Directories and Search Engines : Best Web Directories and Search Engines Order Out of Chaos on the World Wide WebDifferent Ways to Search on the Web: Different Ways to Search on the Web Input URLs, surf links Subject directories Search engines Metasearch enginesWeb Directories: Web Directories Small, selective databases Created by humans not machines Editors select and place sites into categories for easy retrieval User browses categories and links to sites How Directories Work: How Directories Work Browse subject categories Funnel: from categories to web sites Health Yahoo! LookSmart Fitness Open Directory Yoga Most popular sites yogabasics http://www.yogabasics.com/Directory Search Boxes: Directory Search Boxes Use when subject categories don’t match your topic: winemaking in Slovenia Be aware a directory first searches its own select database may automatically default to a search engine if it finds little in its own database LookSmart defaults to WiseNut Open Directory defaults to GoogleWhy Use Directories?: Why Use Directories? Identify major and quality sites Get overview, general information on topic Enjoy serendipity in discovery as you manipulate a small, focused file Small, Selective Directories: Small, Selective Directories Librarian’s Index to the Internet 14,000+ Informine 120,000+ Academic Info 25,000+ WWW Virtual Library Large, Less Selective Directories : Large, Less Selective Directories Yahoo!: 3,000,000+ Open Directory: 3,800,000+ LookSmart: 2,500,000+ HyperResearch Guide Web Search Engines: Web Search EnginesWhat Are Search Engines?: What Are Search Engines? Spiders, crawlers Visits, reads web page, follows its links Index, catalog Giant book containing web page spider finds Spiders update pages and add to index Search interface Sifts through index to find matches to words in searchbox Ranks pages for relevancySearch Engines are Same and Different: Search Engines are Same and Different Search engines are the same Consist of crawlers, index, interface Search engines are different Low overlap of database contents 50% of pages in one not found in another Pages for inclusion found internally, by following links, or by submission Remember: Google doesn’t know it all!How Search Engines Work: How Search Engines Work Spider “capture” web pages Web pages build index, database Interface finds words in database Engine ranks, describes results How engines and directories differ Spiders Capture Web Pages: Spiders Capture Web Pages Spider “reads” database text into index Google ~ 100K, Yahoo ~ 500K Spider follows page links, reads new pages into index Spider returns to sites (every month or two) and look for changes Dead sites removed, current sites updated New sites added (through new links found or submitted by others) Web Pages Build Database: Web Pages Build Database Current web size: over 15 billion pages Each database has different pages No engine’s database covers it all Google ~ 29% (4.3 billion+) Yahoo! ~ 20% (3 million+) HotBot ~ 20% (3 billion+) Teoma ~ 13% (2 billion) As pages are updated, nature of database changesInterface Finds Words in Database: Interface Finds Words in Database Provides keyword search box Offers search options to affect results Assumes AND between words: Iraq WMD Uses “quotes” for PHRASE searches: “Cold War” Allows FIELD searching : ti:Russian mafia url:russianmafia Offers Simple and Advanced Search Teoma Engine Ranks, Describes Results: Engine Ranks, Describes Results How “relevance” is determined Location and frequency of search words Title tag, near top of page of indexed text Site popularity ~ how many “clicks” a site get Link popularity ~ how often others link to site Subject popularity ~ link popularity within subject communities (Teoma) Results described, keywords highlightedHow Engines and Directories Differ: How Engines and Directories Differ Computers vs people Spiders select documents Editors select documents Quantity vs quality Engines large, non-judgmental Directories small, want “best” “most important” Technology vs human factor Software ranks items Editors organize pages into subject, categoriesWhy Use Search Engines?: Why Use Search Engines? You need specific rather than general information What role did the Romans play in developing a wine culture in Slovenia? You need a large, comprehensive database in contrast to a directory Note: remember, search engine crawlers grab anything and everything; selectivity depends on you and the engine’s ranking system Top Search Engines: Top Search Engines Google 4.3 billion+ Yahoo (Inktomi) 3 billion+ HotBot (Inktomi) 3 billion+ Teoma 2 billion+ HyperResearch GuideMetasearch Engines: Metasearch Engines Metasearch Engines: Metasearch Engines Technologies that search several search engines at the same timePros: Pros Increase results when one search engine produces little Save time by searching several engines at once Show results of several engines on one pageCons: Cons Retrieve too many hits Retrieve less relevant results Cannot read individual search syntax well Cannot tell if syntax requires terms in upper. lower case (OR~or~and~AND? Cannot tell if title, URL searching allowed, etc. Contain mix of major search engines, not allTop Metasearch Engines: Top Metasearch Engines Vivisimo Clusters results into subject folders Dogpile Refines results, covers major engines Ez2find Includes most major enginesA Few Words About the Web and Search Engines: A Few Words About the Web and Search Engines What’s In Search Engines?: What’s In Search Engines? Business, commercial information Organizational publications Government resources Some magazine, newspaper articles Some scholarly information Teaching materials, unpublished articles Books, articles whose copyright expiredWhat’s Not in Search Engines: What’s Not in Search Engines Most books and periodical articles Current, past research, fiction, non-fiction Reference materials Best current encyclopedias, handbooks, business advisory services, etc. Bulk of human knowledge and research Where can some of this information be found? In libraries in print or via subscription databases available in libraries, institutions, organizations Widening Google and Yahoo’s Eyes for Scholarship: Widening Google and Yahoo’s Eyes for Scholarship OAIster University of Michigan and Yahoo project 3,000,000 scholarly documents 277 institutions involved Open WorldCat OCLC and Google project 2,000,000 books in Google index Open access to 54 million books is goalSearch Tips: Search Tips Check “advanced” search and options Learn about AND, OR, ANY, ALL, PHRASE Know how to search in titles, URLs Spell it right Switch engines, get different results Keep up to date about search engines Newspapers and magazines Library web sitesLearn to Evaluate Web Sites: Learn to Evaluate Web Sites Accuracy Is information reliable? Where is it from? What does URL tell you? (com, .org, .gov, .edu)? Authority Author’s credentials? Address, email given? Content and Currency Purpose of site: inform, sell, propagandize? Date? Documentation Are sources given, footnotes? Are other links given? Find and Evaluate: Find and Evaluate Use Google and find Website titled: The Burmese Mountain Dog Evaluate this site for Accuracy Authority Content and Currency Documentation Is it a trustworthy Web site?