1. 1 Pertemuan 20 Searching Mechanisms Matakuliah: M0284/Teknologi & Infrastruktur E-Business Tahun: 2005 Versi: >

2. 2 Learning Objectives Describe the role of search engines in e- business Explain how search engines work Describe use of search engines in intranet and extranet environment Identify important search engines in the market Describe a flexible search strategy

3. 3 Directories and Databases Searchable subject/ topic directory yahoo.com – A hierarchy of topics entries are submitted to the site, verified and included in the directory. Good quality control Virtual Libraries http://sunsite.berkely.edu/internetindex Specialized databases both content and index –Lexis-Nexis, Medline, Dialog

4. 4 Meta-Search Engines Coordinate the services of several search- engines Dogpile www.dogpile.com Metacrawler www.metacrawler.com

5. 5 Search Engine Evaluation Recall –Ratio of pages returned to total volume of pages on the world wide web Precision –Ratio of pages returned that are relevant Conflicting nature of the above two criteria

6. 6 Search Engine Evaluation Directories like Yahoo are high in precision, poor in recall General sites such as Altavista are high in recall and poor in precision Design challenge in search engine is to have both high precision and recall

7. 7 Search Engine Evaluation Search life cycle – Initial phase exploration phase high recall is required –Later phase exploitation phase high precision is required

8. 8 Popular Search Engines Google Yahoo Altavista Northern Light Lycos Excite

9. 9 Flexible Search Strategy Determine specificity of search required –In exploration or exploitation phase? Choose a search engine that suits the specificity of search –meta-search engines for initial phase of exploration Build a search query –Boolean statements

10. 10 A Search Example How to develop a small business in the engineering area and obtain a prospective list of customers –Start with a virtual library

11. 11 A Search Example

12. 12 A Search Example Response to query “small business”

13. 13 A Search Example A site on small business

14. 14 A Search Example Business Week Site on Small Business