Tuesday, 8 January 2013

Search engines + narrowing results

There are many competing search engines, each using slightly or radically different techniques to come up with their results. There is one globally dominant company, and we easily understand what is meant if someone suggests we 'google it'! However, even Google has more limited success in some countries such as China.

There are some files you need to access at Y:\ICT\KS3\Year 7\The Internet.

The links below will help you to explore and differentiate between the competing search engines, and understand how to get better, more specific/relevant search results.

Click here for an interactive demo of how Boolean search terms work
Some of the techniques for better search results we'll explore include...
  • using the minus sign: a search for salsa finds everything to do with food and dance; if we only want the food-based reults we change our search to -dance salsa. The Boolean operator NOT also works like this: salsa NOT dance will achieve the same results.
  • using the asterisk (SHIFT+8) symbol: if we search adam ant we get 5.2m hits, but if we search adam ant* we get 31.9m hits. Why? Because the * tells the search engine to include all words starting with ant, which is useful here because Adam Ant was originally in a band called Adam and the Ants! You use the * if there are several relevant variations of one of your search terms
  • adding more words: we're usually looking to reduce the number of hits to get more relevant results, and adding more words usually does this. headlines 2000 gets 195m hits; headlines year 2000 reduces this to 132m; uk headlines year 2000 reduces this to 102m
  • word order: whichever words we put first are ranked as more important in the search, which is why I put uk first in the above example!
  • speech marks: if we put "" round words the search engine will look for that exact phrase. "adam ant" gets half as many hits as simply adam ant, and they're more relevant
  • and finally... The Boolean operator AND tells the search engine not to simply look for web pages with any of the words in the search phrase, but to look for results with all of the terms you put AND between. So, if I search for uk newspaper headlines year 2000 I get 153m hits. If I amend this to uk AND newspaper headlines year 2000 I only get hits which have both UK and newspapers: I now get 144m hits. The search uk AND newspaper AND headlines AND year 2000 gets 104m hits. If I amended this to headline* it jumps up to 365m!
Look at the four results screenshots below: which one do you think returned the most useful answers?

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