Thursday, January 15, 2009

For years it has been thought that Google is using word relationship technologies, one of which has been dubbed “latent semantic indexing,” or LSI, and when you think about it, this concept is really something out of a Sci-Fi movie. Not only does Google index certain words that appear in a document, but it examines the document collection as a whole, comparing it to other documents in order to determine which documents contain similar word choice. The really amazing thing is how well it correlates these semantically similar pages in a way that is strikingly close to the way a human would classify the same information.

We recently discovered an excellent example of this that almost makes it seem like an actual human being made changes to a search result because of the relevancy of the result. We did a search for “gag me with a spoon.” We all remember that phrase right? Well, some of the younger folk these days have no idea what it means, so a simple Google search is the logical solution. As it appears below, the sixth result for this query is a Wikipedia entry about “Valspeak.”



It just so happens that Valspeak is the term used to describe the kind of speech, or sociolect, associated with the phrase, “gag me with a spoon.” In other words, it is the language of “valley girls.” So that doesn’t seem so uncommon so far because you might think there are some examples of Valspeak, of which one would be “gag me with a spoon.” But the amazing thing is that this phrase does not appear even once on the entire page. Scour it as much as you like, but the phrase we queried is nowhere to be found. This is simply an excellent example of latent semantic indexing in which Google has taken terms that do appear, such as “valley girls,” “surfer slang,” “Southern California,” or even “Clueless,” and compared it to pages containing the phrase “gag me with a spoon.” As you might guess, there are probably a large number of commonalities with these pages, and thus, Google succeeds in placing a search result that is actually quite relevant to the query but that does not even contain that term.

So what does this mean for search marketers? Anyone can easily do a search to find the terms that Google considers relevant to certain keyphrases. Simply do a search for ~search marketing. The ~ character causes semantically related terms to appear in bold in the search results so that terms like online marketing and Internet marketing appear. It might be a good idea to include some of this terminology along with target keyphrases in order to take full advantage of latent semantic indexing and increase the relevancy of your pages.


About the Author: Peter Hamilton is the Project Manager in charge of the Seattle office of ArteWorks SEO. His interest and experience in search engine optimization is largely focused on social media optimization and multi-media facets of exposure specifically video SEO. To learn more about this search engine optimization company, visit www.arteworks.biz.