1. Session 5: How Search Engines Work

2. Focusing Questions How do search engines work? Is one search engine better than another?

3. Instruction

4. Framing Our Work If you’ve been near kids and computers – and all of us have, whether in class, the computer lab, the library, or at home – you’ve seen them on the Internet. Have you noticed how they search?

5. Framing Our Work Most students use one of three search engines use only simple search terms look at only the first page of results

6. Framing Our Work It’s important to teach them how to find good information in a strategic way. There are lots of ways of getting information on the net. Some are better than others.

7. Framing Our Work Understanding how search tools work, and how they differ, is the first step in helping students create their own “best ” strategy for finding the information they seek.

8. Teaching It’s amazing, really – you type in a couple of words into a box, hit the GO key and in mere seconds, you get a list of websites on your topic. Just how does this happen? Let’s take a look at what’s behind these long lists of results.

9. Ever wonder how an Internet search that takes.5 seconds to make is able to give you a list of 3 million results? Source: Teaching Zack to Think: WebLiteracy for Educators course (http://nlcourses.com)

10. Ever notice that of the 3 million results, many have little to do with the keywords you used in your search? Source: Teaching Zack to Think: WebLiteracy for Educators course (http://nlcourses.com)

11. Ever waste your time trying to find something on the Internet that you know exists, but you cannot find it? Source: Teaching Zack to Think: WebLiteracy for Educators course (http://nlcourses.com)

12. Let’s see how this happens by examining…

13. How Search Engines Work

14. Search Engines collect information using programs called robots or spiders Information collected: text, titles of pages, and meta-tags (words a web author uses to describe his or her page)

15. Collected information goes into that search engine’s database

16. When you conduct a search, your keywords are matched against the search engine’s database. Breast Cancer Rap Music Ancient Egypt

17. When you conduct a search… Search engines do not search the entire web … They only search within their own databases Breast Cancer

18. That is why your results appear so quickly! Picture source:http://www.sbi- secureit.com

19. This is why you DON’T see new web sites (they may take weeks to appear)

20. This is why you DO see all those error messages (the site was there when the spider collected it!) 404 FILE NOT FOUND

21. Search engines do not all work the same way some focus more on pages some crawl the web more often others evaluate keywords differently (giving different weight to keywords than metatags, etc)

22. If you want to know the latest breaking news about Search Engines, go to http://searchenginewatch.com/

23. Is one search engine better than another?

24. Not necessarily, BUT they provide different results from the same search terms!

25. CLASS POLL: How many of you use more than one search engine on a regular basis? When searching for information, how many of you use more than one search engine to try and find your answer?

26. Let’s see what happens when we compare the result lists from two different search engines

27. Comparing Search Engine Results

28. vs.

29. For our comparison, we will use this site: Thumbshots.com Ranking http://ranking.thumbshots.com/

32. With, you can see the results of several search engines at the same time Another way to compare search engine results is by using http://www.dogpile.com/

35. Know which search tool will produce the best results for any particular query Use more than one search tool if necessary Find content-specific databases on a particular subject The key to good results:

36. Guided Practice So let’s see how this would play out in the world of your students. We’re going to take a topic and see what sites come up using three different search engines. We’ll see what sites your students will miss if they just use one of them.

37. Guided Practice I’m going to do this for the topic Ancient Egypt. In particular, I’m going to look for information on government in Ancient Egypt Google Yahoo Ask

38. Work Time

39. At this time, We’ll be working in pairs or fours to compare search engine results on one of the topics below Government in Ancient Greece Women in Ancient Rome

40. Work Time In your group, you will: Select three search engines to examine For each, look at the “top 10” results Compare results across search engines

41. Work Time As you look at the sites, ask yourselves: Which search engine provided me with links that were relevant and presented the information in an appropriate level of language for my students?

42. Share

43. Today we had a chance to go behind the scene, so to speak, to see how search engines work – how they find sites, organize them, and how those results lists come to be. Share

44. We learned a few easy ways to compare the results from different search engines. When we compare result lists, we can see that the websites that one search engine has on its results list can differ dramatically from those of another search engine. Share

45. Let’s see how this worked with our topics. Now we will look at the sites you found and didn’t find using the one or more of the search engines. Who wants to talk about a good site they found on one search engine that was not on the results list of another? Share

46. Comments and feedback: Share

47. New York City Curriculum Resources Information Fluency Continuum Phase: Investigate p. 18 Indicator: uses a variety of search engines to do advanced searching New York City Performance Standards Applied Learning Standard 3a: Gather information to assist in completing project work Applied Learning Standard 3b: Use information technology to assist in gathering, organizing, and presenting information Standards

48. Technology Standards ISTE National Educational Technology Standard (NETS) Standard 5: Technology Research tools: -- Students use technology to locate, evaluate, and collect information from a variety of sources -- Students use evaluate and select new information resources and technological innovations based on the appropriateness to specific tasks. Standards