Search Engine Watch’s Danny Sullivan looks into the reasons why some sites have lost their Google search engine rankings after the new Google update.

Reasons can be summarized as irresponsible linking and SEO, and addtionally the addition of “stemming” to the Google search algo. Here’s a rundown on stemming from Search Engine Watch:

Stemming is the most significant change searchers should be aware of. When you now search on Google, it will automatically look up variations of words. So a search for travel tips behind the scenes is looking for pages that have all of these words, and perhaps others, on them:

travel

travelers

traveling

tips

tip

Stemming is a helpful feature for many searchers to have, since it save you from having to think of many variations of a word.

It would be nice for Google to somehow indicate exactly what terms are being used. AltaVista used to do this in small text at the bottom of results pages, and it’s useful feedback for when a search doesn’t go the way you expect.

Stemming can be overridden. When you enter any search command, in front of a word, stemming is shut off for that word. So:

travel +tips

Would only enable stemming on the word travel while

+travel +tip

Would disable stemming on both terms.