Google Search Starts Weighing User Site Blocking

Just as Microsoft's dominance of the desktop operating system market has made Windows the primary target of malware authors, Google's dominance of the search market has encouraged efforts to manipulate Google's search algorithm, both within Google's guidelines and outside of them.

Hoping to minimize the impact of such efforts, Google in late February altered its search algorithm for U.S. users to make low-quality content less visible and high-quality content more so. The change was deployed in response to news reports and online discussions about the prominence of worthless results in Google searches.

The necessity of the change may also be inferred from the growing market share of Microsoft's Bing search engine, which in conjunction with searches submitted through Yahoo, processed 30% of U.S.-based searches in March, according to Hitwise.

On Monday, Google extended its algorithmic adjustment to all English-language versions of Google around the globe. What's more, the company has begun to incorporate feedback from users who block websites using the blocking mechanism introduced last month. Google fellow Amit Singhal says the company is relying on this feedback in "high-confidence situations."

Previously, Google opted not to use data about blocked domains as one of the more than 200 signals it relies on to determine where Web pages rank for a given search; instead it used the data to validate its own search quality adjustments.

Google made its name with one particular ranking signal, the PageRank algorithm, which proved to be particularly helpful in determining where Web pages rank in search results lists. PageRank treats Web links as implicit votes for relevancy. Now the company is harvesting explicit votes for irrelevancy, the condemnation of the crowd, through its site blocking capability.

Singhal says that the impact of these new signals will be smaller than the algorithmic change introduced last month. Only 2% of U.S. queries are affected, he claims, compared to 12%.

Inevitably, those affected by the change are complaining to Google. But redress may be complicated by the fact Google's users now have a say in search quality.