Most people who use any of the mainstream search engines have at one point or another probably come across a search that returns rather strange, often comedic results. Examples of these are searches such as ‘miserable failure’ which, for quite some time, returned as the top result, a link to the white house biography of George W. Bush, and ‘french military victories’ which returns as it’s top result a fake google page that asks whether you might have been searching for ‘friench military defeats’. In days gone by, when web search was a simple matter of returning the pages containing the most instances of a given word, acheiving results like this took a far different approach than it does today.
The concept of a Google Bomb is relevant to our study of netowrks because most mainstream search engines currently base results on an analysis of the link structure of the web. The idea behind this stems from the thought that a web page, call it ‘A’, is a good result for some query, say ‘b’, if a lot of other web pages link to ‘A’ with a link named ‘b’. Intuitively this makes sense because this way a web page is essentially peer-reviewed by other web pages and is only a good result if other web-pages (people who write pages) consider it a good page.
Google Bombing is a practice that exploits this fact to alter search results. Basically, to make a Google Bomb i.e. to cause a search for’a’ to return page ‘B’, one must simply add links from a lot of other pages to ‘B’ with the link name being ‘a’. This way, when Search engines run their ranking algorithms, they will think that ‘B’ is a good page to display as a result for ‘a’.
While generally this is not a major issue and most major search companies have chosen to do essentially nothing to combat Google Bombs, they are interesting in that they demonstrate how search engines actually rely on the graph structure of the Web to generate results.
See this article for more specifics on Google Bombs. Here is Google’s explanation of their PageRank Algorithm. Google also recently somewhat restructured their search algorithm in order to diffuse many Google Bombs that other search engines still have trouble with. See this blog post from Google for more information.