Google now uses stemming

Google has indeed deployed the stemming of keywords within its search results. Earlier, searching for singular terms (like ‘home garden’) did not show up plurals (home gardens) and vice-versa. Google now considers several variations of the keywords to search for sites in its database to display search results. (garden, gardens, gardening etc.). Seems minor; does it? Actually, this has a far-reaching implication on the competition for the keywords and ranking. Suddenly, the canvas for keyword competition has become enlarged. While for Google users, this feature may be helpful as they now get results from a larger database. From the SEO perspective, one now needs to compete with a much larger set of pages for ranking. Competition for keywords has suddenly intensified.

Google is using its spelling correction tool in search results.

In several search criteria, Google is now deploying its spelling correction tool in the search results. I discovered this when I searched for the term ‘Search Engine Optimisation’ as Asians spell it. Earlier, I used to get results with only ‘s’ in ‘optimisation’. However, now I see results with ‘z’ in ‘optimization’. ‘e-mail solution’ will now fetch ‘email solution’ and ‘e-commerce’ will get ‘ecommerce’. Competition data has increased.

Google has deployed the Hilltop Algo to fine-tune the effect of PR

Most Internet buffs know that Sergey Brin and Larry Page pioneered the PageRank algorithm (named after Larry Page), to refine ranking of sites on search results. This was one of the important factor in Google’s success story since 1998. See details about PageRank here - http://www.google.com/technology

However, there is a basic flaw in the PageRank system. The PageRank (PR) system allocates an absolute ‘value of importance’ to a web page based on the number of sites that link to it. The PR of the linking page is also valued. The higher the PR of the incoming link page, the higher the PR value passed to the linked page. However, ‘PR value’ is not specific to search terms and therefore a high-PR web page that even contained a passing reference to an off-topic keyword phrase, often got a high ranking for that phrase. Krishna Bharat from California realized the flaw in this PR-based ranking system and came up with an algorithm he called ‘Hilltop’ in the year 2000. He filed for the Hilltop patent in Jan 2001 with Google as an assignee. Needless to say, Google realized the advantage this new algo would offer to their ranking system if combined with their own PR system.

I believe that Google has indeed deployed the Hilltop algo in its last algo update in combination with Google’s own algo of PR and relevance. However the Hilltop algo may have gone refinements from its original form before this deployment.