What do you do when you want to find a restaurant in your area? Or when you need a boost on a homework question? Or if you want to research a new place you'll be visiting? You turn to your favorite Internet search engine, of course. These days we take search engines for granted, but there is a lot going on behind the scenes each time you enter a search query into your favorite search engine.
The role search engines play in organizing the massive amount of information on the gigantic World Wide Web is fundamental. The picture below represents all the webpages in the universal web, which contains only webpages that can be accessed via hyperlinks, with their links; each line in the picture represents a link between two webpages. Now that we have a better idea of just how messy, complicated, and expansive the Web is, how could we possibly organize it in a way that will help us find what we need?
The following activity will help us to gain a better understanding of the difficulty of navigating through the World Wide Web without any search engines to guide us.
Without adequate search engines, we would truly be lost. In this WhyDoMath node, we explain some the mathematical ideas used by today's search engines, specifically those used by Google.com.
Google is the most famous and popular search engine today. But what makes Google so special? Why is it more successful than other search engines? Aren't most search engines pretty much the same? See for yourself. Type the search phrase "British Museum Exhibit" into these three search engines:
Yahoo!
Google
Ask.com
Have you ever wondered how search engines actually retrieve the web documents you need? The answer is mathematics. In fact, Google started with the simple mathematical idea of link analysis.
Sergey Brin and Larry Page were both students at Stanford University when
they hit upon their brilliant idea. They turned a math and computer science
research project into a multi-million dollar international business that has
become a household name (and, not to mention, a new verb). I bet they're glad
they paid attention in Math class. And who knows? Study hard, and the knowledge
you gain from your Algebra or Calculus book could help you get a job here:
Refer again to your search results for "British Museum Exhibit" in
Yahoo!, Google, and Ask.com, and compare the first few links. Are they the
same? When you compare the results from queries to various search engines
you probably see roughly the same set of retrieved pages repeated in the
results list from the different search engines. Yet the order of the pages
in each list usually varies. If the search engines find roughly the same
webpages, does this presentation order matter? Who cares what order the results
pages are sorted in? In the "British Museum" query exercise, how many pages
in the results list did you examine? The first 5 webpages? Or maybe the first
whole page of retrieved results? How often do you ever look beyond the first
page of results retrieved by a search engine?
Source: Wall Street Journal April 13, 2007
According to one study published in the Wall Street Journal, 23% of search engine users only look at the first few results, 39% at the first page, 19% look at the first 2 pages, and only 19% look at three or more pages. Still think order doesn't matter?
So how does Google order their search results? The answer, again, is mathematics and the story starts in 1998 at Stanford University.
