Ever heard of Latent Semantic Indexing? If you're a search marketer, the answer is probably yes. If you're a small business owner, there's a good chance the answer is no. That's ok...it's not a magic term that will turn your optimization efforts upside down, but it is a concept you need to know a little something about.

While I have a fundamental grasp of LSI and how it can and will impact search engine optimization, I generally leave the explanation of complex algorithmic processes to people far smarter than I. Thankfully, people like Mike Moran step up to the plate and help the rest of us out now and then.

Mike has a great post over at Internet Evolution that includes a section explains the basics of Latent Semantic Indexing (LSI).

Consider how difficult it is to correctly identify which of several meanings of a word might be the right one for a searcher. When someone searches for "jaguars," for instance, are they looking for the animal, the car, or even the football team? When searchers type in just one word, there's no way for the search engine to know, but the moment a second word is entered, it's often quite clear.

For example, when someone enters "jaguar prices," you know it's the car. And "Mexican jaguar" is about the animal, and "jaguars quarterback" is about the football team. For a human being, it's simple for us to understand which meaning is intended each time, but semantic analysis is one way for computers to figure it out, too.

Now, often a computer could guess right without semantic analysis, because those two-word phrases appear in the right documents. But what about a document that refers to a "Mexican Jaguar dealer"? People who search for "Mexican jaguar" would certainly not be interested, but a typical text search might turn it up, just because it contains the matching phrase. A computer that uses semantic analysis would likely not be tricked so easily, because it detects that the "Mexican jaguar" search is for animal information.

While most of the rest of Mike's article is talking about whether Latent Semantic Indexing is the best form of Latent Semantic Analysis for search engine results...it's the section above that you need to read and digest if you simply want to understand the concept of this fancy term.

I've argued time and time again for my theory of the Pinocchio Effect as the key to understanding where the search engines will go with their algorithms. Understanding the technology that is available to the engines (like LSI) goes a long way toward understanding how the engines are poised to understand more and more "natural language" (as opposed to keyword stuffed copy) over time.

By no means should you stop optimizing your content for the keyword phrases you're targeting, but you should take this concept to heart as you realize how important it is to wrap those keywords into copy that flows naturally.

October 8, 2008

Jennifer Laycock is the Editor of Search Engine Guide, the Social Media Faculty Chair for MarketMotive and offers small business social media strategy & consulting. Jennifer enjoys the challenge of finding unique and creative ways to connect with consumers without spending a fortune in marketing dollars. Though she now prefers to work with small businesses, Jennifer’s clients have included companies like Verizon, American Greetings and Highlights for Children.


Well, we are still stuck at Web 2.0 ....and semantic search is definitely the new era of web and perhaps can be called web 3.0.

The major players in the industry are not likely to switch to Semantic search anytime soon, because in order for it to work correctly all the sites that are in the WWW has to implement some sort of web ontology language on their pages

This might not be a problem for sites that are being created today, because as technology advances, I think it would get easier to publish a web document that can somehow be automatically serialized with the resource description framework (RDF). But for legacy sites ...this is really going to be a pain!

But eventually the whole web has to use Semantics one day. There are already few 'so-called' semantic search engines out...but the result hasn't been very promising.

Great piece of info.

Even thou I knew that information, I think that this is the kind of articles that a few of my clients should read and understand that trying to rank well for only one word it's not that productive for your web site.

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Search Engine Guide > Jennifer Laycock > A Little Primer on Latent Semantic Indexing