Search engines


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Search engines

  1. 1. Search Engines
  2. 2. Starter Activity: Search Engine Secrets Why do you think search engine companies like Google are secretive about how their search engine works? Search Engines
  3. 3. In this lesson you will learn about how search engines work and how they rank pages. You will check the page ranks of web pages and create an annotated diagram to explain how they are ranked. Lesson Objectives  Understand how a search engine works  Understand the different jobs of a search engine  Be able to describe how the PageRank algorithm works  Be able to check the PageRank of a page Search Engines
  4. 4. Search Engines •A search engine is a set of programs which are used to search for information in a database •There are over 250 search engines in the world •They help people organise and display information in a way that makes it easy to access •As well as providing a website address they can locate reviews and compare prices Search Engines
  5. 5. Task 16: Search Engine Montage Using individual images create a collage of search engine logos. Search Engines
  6. 6. Task 17: Ask Vs Yahoo Using the two search engines above find out the meaning of the word: “imbroglio”. Discuss with your elbow partner which search engine you prefer out of the two and why. Search Engines
  7. 7. Watch the How Search Works video, this will introduce you to how search engines work. Search Engines
  8. 8. Working of Search Engines There are three main jobs of a search engine: 1.Crawling – a process of going from web page to web page via the links to seek out new content, including updates to files and web pages. 2.Indexing – the programs index the information, pulling out specific keywords to categorize it. The data is stored in an online index database. 3.Searching – the engine examines its index and provides a listing of best-matching webpages. Search Engines
  9. 9. Search Engines Algorithms Search engine algorithms are unique to every search engine. There are some common things: 1.Relevancy – check for keywords on webpages that are in your search 2.Individual Factors – the number of pages and the frequency that a search engines indexes 3.Off- Page Factors – number of times a link on a webpage has been clicked to visit another webpage Search Engines
  10. 10. Google Search Engine •Created by Larry Page and Sergey Brin •Founded September 4, 1998 •Most popular search engine Search Engines
  11. 11. Google - PageRank Algorithm 1.Used to determine a page's importance 2.Important pages receive a higher PageRank 3.PageRank It is measured from 0 -10 4.The higher the PageRank the higher up the webpage will be in the search results 5.PageRank is based on backlinks 6.The more quality backlinks the higher google PageRank Search Engines
  12. 12. Page Rank Algorithm Compared to Social Networks People have links to people. If you have links to famous people and they have link backs to you, your page rank will be high! Search Engines
  13. 13. Task 18: PageRank Check 1.Go to: 2.Click on the ‘Check Page Rank’ 3.Check the PageRank for: 4. Which web page has the highest page rank Search Engines
  14. 14. Task 19: PageRank Illustration Create a diagram like the example below to illustrate how PageRank works then annotate your diagram to explain how the algorithm works. Search Engines
  15. 15. Plenary: Brain Dump Brian Dump what you now know about search engines and the PageRank algorithm. Search Engines
  16. 16. Keywords  Understand how a search engines work  Understand the different jobs of a search engine  Be able to describe how the PageRank algorithm works  Be able to check the PageRank of a page Objectives  Search Engines  Backlink  PageRank  Algorithm  Searching  Crawling  Indexing  Database     Search Engines