TOPICS TO BE COVERED What is a search engine? Purpose of search engines? How search engine opererates? How we can improve use of search engines? Advantages of search engines Disadvantages of search engines Conclusion
Search Engines Search engines are programes that allow the user to enter keywords that are used to search a database of web page Each search engine searches in a different way and searches different sites. That is why doing a search in one search engine will produce different results than doing the same
Purpose of search engines Helping people find what they are looking for Starts with an “information need” Convert to a query Get results
How search engine operates? Crawling the web, following links to find pages Indexing the pages to create an index from word every place it occurs Ranking the pages so the best one shows first Displaying the results that in a way that is easy for the user to understand
How we can improve use of searchengines You can get better results from an Internet search engine if you know how to use: 1. wildcards 2. Boolean operators
Wild Cards•A wild card is a special character which canbe appended to the root of a word so that youcan •" Wildcards possible to searchsearch for all allow youendings to that root. simultaneously for several words with the same stem.•Example: "educat*“, "smok*"
Boolean operators 1.AND 2.OR 3.NOTAND• Using the boolean operator “AND", it is possible tonarrow a search so that you get quite a limited set ofresults.OR•The boolean operator “OR" has the opposite effect ofexpanding a search.NOT•Another common operator is “NOT" which acts to limit asearch as well.
Advantages of searchs The indexes of search engines are usually vast, representing a significant proportions on the internet. The large number of variety of search engines enriches the internet, making it least appear to organiszed. The growing sophistication of search engine software enables us to presicely describethe information that we seek.
Disadvantages of searchengines They do not crawl on the web in the“realtime”. If a site is not linked it may not be accesible. Not every page of a site is searchable. Special tools are needed for the Invisible or Deep web. Few search engines search the full text of web pages
ConclusionThe primary goal of search engine is to provide highquality search results over a rapidly growing worldwide web.Search tools like Google search engine employs anumber of techniques to improve search qualityincluding page rank, anchor text, and proximityinformation.As the technology advances at an unimaginablepace, it is not unwise expecting an efficient searchengine, which addresses all the needs.