Latent Semantic Indexing and SEO

Latent Semantic Indexing and SEO – Indexing has always been considered a highly targeted science. Enter a search query into Google search, and the pages that are displayed are generally optimized towards that exact word or term. However, in their ongoing battle to serve the most relevant and natural pages with genuinely helpful information, Google has incorporated latent semantic indexing (LSI) into its algorithms.

What Is LSI?

LSI is a unique indexing method that potentially takes Google’s search one step closer to becoming human in its thinking. If we were to manually search through web pages to find information related to a given search term, we would likely generate our results based on the site’s theme, rather than whether the word exists on the page or not.

Why Search Engines Might Adopt Latent Semantic Indexing

The highly rigid form of keyword indexing also made it easier to implement black-hat SEO techniques. Search engines could be manipulated into ranking a site highly by using a set formula. Originally, cramming a page with a particular keyword or set of keywords meant a site would rank highly for that search term. The preceding set of algorithms ensured that your link profile played a more critical part than your keyword density. Reciprocal linking soon followed again, making it possible to manipulate search engine spiders by exchanging links with tens, hundreds, or thousands of websites.

Reciprocal linking was soon overshadowed as Google, and to a lesser extent, Yahoo and MSN gave less weight to reciprocal links compared to one-way inbound links.

Latent Semantic Indexing is another compelling method to make their result pages appear more natural, with pages filled with natural content.

The Effects

The introduction of LSI has already led to some dramatic changes in search engine results pages.

Sites that previously performed well due to an impressive link profile based on a single keyword have found their pages slipping in the rankings. Other pages with a more diverse portfolio of inbound links are taking the lead with search terms for which they had not previously performed.

SEO is far from dead because of LSI; in fact, if anything, it has probably increased the need for professional, white-hat SEO on your website.

The field of SEO, though, has almost certainly changed.

Website content copywriting for Google’s benefit is no longer just about keyword density and placement, as it once was. Link-building techniques will also need to change to incorporate LSI algorithms, but it can still be done.

Writing Content For LSI

If you optimize solely for Google, then a web page can, theoretically, be naturally written and optimized for search engines. When we write, we instinctively include the appropriate keywords in our text. To avoid repetition (or keyword optimization, as it was once called), we often replace some instances of these keywords with words of the same or very similar meaning. We naturally include the plural or singular form of a keyword as well as different tenses and a number of different stems of that keyword. In the eyes of the LSI algorithm, this is all good news.

Looking At Your Link Profile

A link profile should no longer consist of thousands of links with the exact anchor text (that of your primary keyword). There’s no reason to panic if you already have this kind of profile. Instead, you should look at relevant and similar terms and improve your link profile by gaining links using these as your anchor text.

What It Offers Web Searchers

From the perspective of web searchers, LSI offers several distinct advantages over traditional indexing. For example, LSI recognizes that the word “engine” in “search engine optimization” is not related to searches for terms like “steam engine” or “locomotive engine” and is instead related to Internet marketing topics. In theory, LSI results provide a more accurate list of results, as well as a broader range of pages still focused on a particular subject.

Where Google Leads, Others Generally Follow

It is widely acknowledged that Google is the search engine at the forefront of latent semantic indexing. On the whole, they try to generate results pages that are literally filled with genuine, practical results, and LSI certainly provides another string to their bow. Yahoo and MSN, for now, seem more than happy to go along with a keyword-specific index. Although Yahoo is known to consider both singular and plural keyword variations, as well as keyword stemming, when evaluating keyword density.

The Effect On Your Website

How it affects the individual webmaster depends on how they currently promote their site.

Suppose the pages are filled with natural content, including keywords and keyword alternatives, and the link profile is similarly diversified for several related keywords. In that case, it won’t make much of a difference. However, if all your efforts have been concentrated, either on-page or off-page, on a single keyword, then it’s time to rebalance.

# Latent Semantic Indexing and SEO

About the Author:
Post excerpts from Matt Jackson’s homepage content, author for WebWiseWords.