Google Search Appliance
Technology Overview
Google stands alone in its focus on developing
the "perfect search engine," defined by co-founder Larry Page
as something that, "understands exactly what you mean and gives
you back exactly what you want." To that end, Google has persistently
pursued innovation and refused to accept the limitations of existing
models. As a result, Google developed its own serving infrastructure
and breakthrough PageRank™ technology that changed the
way searches are conducted.
From the beginning, Google's developers recognized
that providing the fastest, most accurate results required a
new kind of server setup. Whereas most search engines ran off
a handful of large servers that often slowed under peak loads,
Google employed linked PCs to quickly find each query's answer.
The innovation paid off in faster response times, greater scalability
and lower costs. It's an idea that others have since copied,
while Google has continued to refine its back-end technology
to make it even more efficient.
The software behind Google's search technology
conducts a series of simultaneous calculations requiring only
a fraction of a second. Traditional search engines rely heavily
on how often a word appears on a web page. Google uses PageRank™ to
examine the entire link structure of the web and determine which
pages are most important. It then conducts hypertext-matching
analysis to determine which pages are relevant to the specific
search being conducted. By combining overall importance and query-specific
relevance, Google is able to put the most relevant and reliable
results first.
- PageRank Technology: PageRank performs
an objective measurement of the importance of web pages by
solving an equation of more than 500 million variables and
2 billion terms. Instead of counting direct links, PageRank
interprets a link from Page A to Page B as a vote for Page
B by Page A. PageRank then assesses a page's importance by
the number of votes it receives.
PageRank also considers the importance
of each page that casts a vote, as votes from some pages are
considered to have greater value, thus giving the linked page
greater value. Important pages receive a higher PageRank and
appear at the top of the search results. Google's technology
uses the collective intelligence of the web to determine a page's
importance. There is no human involvement or manipulation of
results, which is why users have come to trust Google as a source
of objective information untainted by paid placement.
- Hypertext-Matching Analysis: Google's
search engine also analyzes page content. However, instead
of simply scanning for page-based text (which can be manipulated
by site publishers through meta-tags), Google's technology
analyzes the full content of a page and factors in fonts, subdivisions
and the precise location of each word. Google also analyzes
the content of neighboring web pages to ensure the results
returned are the most relevant to a user's query.
Google's innovations don't stop at the desktop.
To bring its accurate and speedy search results to users accessing
the web through portable devices, Google also pioneered the first
wireless search technology for on-the-fly translation of HTML
to formats optimized for WAP, i-mode, J-SKY, and EZWeb. Currently,
Google provides its wireless technology to numerous market leaders,
including AT&T Wireless, Sprint PCS, Nextel, Palm, Handspring,
and Vodafone, among others.
Life of a Google Query
The life span of a Google query normally lasts
less than half a second, yet involves a number of different steps
that must be completed before results can be delivered to a person
seeking information.
