Thursday, June 3, 2010

About Latent Semantic Indexing (LSI)


Also known as Latent Semantic Analysis (LSA), this technology allows Google to analyze and quantify related keywords within the larger set of content on a web page. Think word synonyms, different word endings, etc. Lots has been speculated about the extent that latent semantic indexing influences ranking.

It is a complex technology, particularly in how it may be implemented. The effect of LSI on your rankings is not well understood, but it means your page may rank better for a related keyword, one that may not even be on the page, than your primary keyword!

Use Keywords in the Following Places

The following are places where keywords should be used on your web pages. The first four items are more important, with Google giving weight to keywords found in the title and link anchor text more than any of the other locations.

• Title: keywords. Keywords should appear as first or second word in the title.

• Link (anchor) text: keywords. The clickable portion of links.

• Headings:




, etc. Use a stylesheet (CSS file) to control the size of heading text to make it blend in better.

• First paragraph of page (first 20 words):


Bold and/or italicize keywords also.

• Last paragraph of page:


• Drop-down boxes:

• URLs:

• Folder & file names: keywords/keywords.html, keywords.gif

• Image ALT text: ”keywords” for graphical links

Some people abuse H1 tags by wrapping them around entire pages of content or by using multiple H1 tags on a page.

This is a bad idea and borders on spam – the H1 tag should be used as a page headline. It is perfectly legitimate to reduce the size of H1 text using a style sheet but that’s about it. As a result, Google may be discounting H1 so it may carry less weight for ranking moving forward.
The same can be said about image ALT text – some people put entire paragraphs of content in them for each image on a page.

It is perfectly legitimate to put keywords relating to the image but that’s it. Similarly, image ALT text now carries less weight than before. Images that are clickable (wrapped in a HREF link tag) do not appear to have a discounting - yet.

Proper Internal Link Structure

Besides the title of a page, Google places special importance on the use of keywords in the text of links. This means you need to structure your links correctly.

Ideally, you should only use text links on your site as opposed to graphical “button” links. Google looks for keywords contained in link anchor text – the clickable portion of the link. Google cannot see graphics-based links – all it has to go on is the ALT attribute for image tags, which doesn’t carry as much weight.

Keywords in link text should match keywords found on the page that the link points to – especially in the title of the page.

Here is an example of the ideal link structure for Google. Of primary importance is the use of keywords in link anchor text (text between the tags). Note also the use of keywords in the actual name of the graphics file.

Text-Based (Ideal) Link Structure:

your keywords

If you must use graphics-based links on your web pages, be sure and fill in the ALT text attribute of the image tag as follows:

Graphics Link Structure:


What Google Ignores

Google ignores the following elements on your web pages. Due to their abuse and misuse, META tags are a thing of the past with Google!

• Information in the tag

• Information in all other META tags (see META “Description” tag caveat)

• Information within the tag

• Information within the


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