Oct 28
Has Google Changed PageRank Algorithm to Punish Critics, Internally Linking Networks?
October 28, ‘07 — It appears from the buzz in blogosphere that some time in past week search giant Google has changed its PageRank algorithm to punish its critics, internal linking networks and illegitimate webmasters.
Forbes, CNET’s News.com, The Sydney Morning Herald and many others writes on the Google changing its PageRank calculations.
SMH writes, “In the brave new world of online media, fortunes can be won and lost on the whim of Google’s key search algorithm. And when, without warning, Google tweaked that mathematical formula this week, there was panic on the world wide web.
Swarms of bloggers and webmasters of major sites like Washingtonpost.com, Forbes.com, Engadget.com and SFGate.com noticed a downgrading in their PageRank, Google’s measure of a web page’s value. A site’s PageRank impacts not only its ranking in Google search results but also the price it can charge advertisers. A drop in ranking can have serious financial consequences, especially for smaller operators.
The search giant, through its dominant search engine and AdWords/AdSense network, is relied on by millions of websites not only for traffic referrals but for monetisation as well.
Ironically, in the ultimate democracy that is the internet, Google reigns as virtual dictator. By changing the way it ranks sites in search results, it has the power to effortlessly shape the digital economy and manipulate the incomes of millions of web businesses around the world.”
Forbes: “Google, for online businesses, has the impact that Alan Greenspan once had on the financial markets. Online companies pounce on every whisper or cryptic comment from Google about how it ranks pages as an indicator–up or down–of how online traffic will flow for millions of Web sites.
On Thursday, Web site administrators for major sites including the Washingtonpost.com, Techcrunch, and Engadget (as well as Forbes.com) found that their “pagerank”–a number that typically reflects the ranking of a site in Google results for key search terms–had dropped precipitously according to Google Toolbar, a software program that tracks Google’s assessment of a site.”
CNET’s News.com: “Well, speculation in the blogosphere today has it that Google has decided to punish popular sites that accept paid links to lesser sites. As Valleywag puts it, “Google’s bean counter, naturally, would prefer that you pay Google for sponsored links instead.
Anyway, part of the buzz about this move is that some of the sites that are taking PageRank hits are the very sites (Search Engine Journal, Copyblogger, Search Engine Guide and the Blog Herald, among them) that cover search engine optimization issues, and some suspect that perhaps the search giant is punishing them for being critics.”
PageRank algorithm explained by Wikipedia: Simplified PageRank algorithmAssume a small universe of four web pages: A, B, C and D. The initial approximation of PageRank would be evenly divided between these four documents. Hence, each document would begin with an estimated PageRank of 0.25.
If pages B, C, and D each only link to A, they would each confer 0.25 PageRank to A. All PageRank PR( ) in this simplistic system would thus gather to A because all links would be pointing to A.
But then suppose page B also has a link to page C, and page D has links to all three pages. The value of the link-votes is divided among all the outbound links on a page. Thus, page B gives a vote worth 0.125 to page A and a vote worth 0.125 to page C. Only one third of D’s PageRank is counted for A’s PageRank (approximately 0.083). In other words, the PageRank conferred by an outbound link L( ) is equal to the document’s own PageRank score divided by the normalized number of outbound links (it is assumed that links to specific URLs only count once per document). In the general case, the PageRank value for any page u can be expressed as: i.e. the PageRank value for a page u is dependent on the PageRank values for each page v out of the set Bu (this set contains all pages linking to page u), divided by the number L(v) of links from page v. And Google put it this way, PageRank Explained: PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page’s value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at considerably more than the sheer volume of votes, or links a page receives; for example, it also analyzes the page that casts the vote. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.” Using these and other factors, Google provides its views on pages’ relative importance. Of course, important pages mean nothing to you if they don’t match your query. So, Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to your search. Google goes far beyond the number of times a term appears on a page and examines dozens of aspects of the page’s content (and the content of the pages linking to it) to determine if it’s a good match for your query.
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