Google said the change would raise the ranking of high-quality Web sites and reduce those of smaller sites, which cover 12% of search queries.
Places known as content farms that churn out sometimes mindless articles based on what they are looking for people recently have worked their way to the top of search results, frustrating some Google users. High rankings in search results is fundamental, because it allows Web sites to get more traffic and bring in more business through the sale of goods and services or advertising.
"I haven't seen as much negative attention on Google results as in the last month or two — was fairly unprecedented," said Danny Sullivan, editor of Search Engine Land and an expert in the field.
Convince users that have the best results is crucial for Google, whose reputation and the front door to the Web depends on them. Although there were many engines before Google search, it became the dominant player because its technology has produced better results for users. If people start to doubt the quality of its results, Google risks losing them to competitors.
While the so-called contained companies may provide useful information, many of their articles are of questionable value but get high ranks in searches. For example, an article by eHow on how to make friends in college includes tips like "consider joining a sorority or fraternity" and "remember having a good time, laugh and smile".
Google makes about 500 changes a year for the algorithm, or formulas, which runs the search engine, most of them minor. Amit Singhal, a Google fellow who worked on the most recent change, said in an interview that users were likely quickly notice this one, which was announced late Thursday.
"We made a change we influenced sites low quality at this level in years," said Mr. Singhal. "It's a clear evolution algorithm as the Web is evolving, the content on the Web is constantly evolving, is evolving the user expectation."
Google still dominates the search market, with a percentage share in the United States and 66 one greater in many other countries, according to comScore, a company of Web analytics. But it looks ambitious competitors, especially the Microsoft Bing.
Hitwise, an analytics firm, measures how happy users are with their research looking at how many were successful, i.e. the user remains the first site they click. Bing, 82% of searches are considered successful. To Google, the figure is 66 percent.
"This change is about more than just clean content farms," said Chris Copeland, chief executive of GroupM search, a search marketing company that is part of the WPP Group advertising company. "Google has a problem of relevance, and are trying to do something about it."
Google has made the change after the tech bloggers, industry analysts and everyday users complained that the search results were useless pages. The answer can help the reputation of Google, said Mr. Sullivan.
"The change may not necessarily improve the results — hopefully will be — but it will definitely improve the perception of Google," he said.
The new algorithm change does not address the full scope of techniques that i use to manipulate Google sites. Is a constant mouse game — just Google makes a change, Web developers, imagine a way around it.
When the search engine Google was introduced in 1998, was its main advantage was the number of times other sites linked to a particular page, weighing those links as endorsements. But as people quickly learned to manipulate such links, Google search began to focus more on other factors, too. Google has punished the e-commerce sites, including j. c. Penney, to inflate their rankings paying for links from unrelated sites.
"Our algorithm clearly being attacked by these techniques every day," said Mr. Singhal. "However, with the amount of information that we have, we're pretty far ahead in the game".
Although the announcement of Google did not explicitly mention content farms and the company declined to say which sites appear lower in the results, Matt Cutts, who directs the Google team fighting spam, spoke about content farms in recent weeks and said Google was working on ways to address them.
"There are some farms contained that I think would be fair to call it spam, in the sense that the quality is so poor that people complain," Mr. Cutts said in a recent interview.
Sites that are often given the label "content farm" Associated Content include Yahoo, AOL and demand Media's seed eHow and Answerbag. Media request, for example, use software to keep track of what people are searching for on Google and other sites, generates titles based on these researches and pay small amounts of freelancers to write articles.
Critics of these sites has been on the radar of Google, and the company said that he had been working on addressing these issues for over a year. This winter, average request went public, and its shares jumped 33 percent on its first day of trading; Now it is worth $ 1.9 billion. Around that time, a tech blogger began to write posts as one who complained that a Google search for new dishwasher had produced results useless.
Of course, the quality of a particular site is subjective. To determine the quality, Google does things like track searches "boomerang", when people click on a link and quickly click back to results and ask people to compare the search results.
Media request, which is based on traffic from Google for its livelihood, said in a blog post on Friday that it applauded the changes and that it was too early to determine the long-term effect on sites in question. This week, Richard Rosenblatt, Executive Director of the request, said he was working to bring readers from sites other than Google and introduced a site that discusses the quality of the application. Stock company significantly lower open Friday but closed 1.6% higher to $ 22.96.
Some consultants that allow websites to improve their search rankings said sites like demand could not feel the weight of the change. They said Google's real target was hundreds of companies no-profile post copies of the same text on hundreds of websites.
And many of the sites will discover a new way to track your Google rankings, said Mr. Copeland GroupM search.
"This is a group of people who will analyze this change, return with a new strategy on Tuesday and be ranked Thursday," he said. "It's like a kind of what happens when they get busted drug dealers. Not finding new jobs. They pass the angles ".
David Segal contributed reporting.
