What is PageRank?
PageRank is a numeric value that represents how important a page is on the web. Para Google, when one page links to another, it is as if the page that has the link, voted to the linked page. The more votes you have a page, more important the page. Also, the importance of the page that vote determines how important the vote. Google calculates a page's importance from the votes they obtained. In calculating the PageRank of a page you consider how important every vote.
PageRank es, para Google, how to decide the importance of a page. Is important because it is one factor which determines the position of a page results. It is not the only factor that Google uses to position the pages, but it is a very important.
Henceforth, refereriremos as in the PageRank “PR”.
Not all links are counted by Google. E.g., filters all links from link farms known. Some links can cause a site to be penalized by Google. They know that webmasters can not control which sites they link, but they can control their own links page. For that reason, links to a website can not hurt, but links from a site can be harmful if you link to penalized sites. So you have to be careful with the links on our page. If a site has PR0, this is, normally, a website penalized and discouraged really link to it.
As PageRank is calculated?
To calculate the PageRank of a page, all inbound links are taken into account. These are links on the page and off-page links.
PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn))
This is the equation that calculates a page's PageRank. It is the original that was published when PageRank was being developed, and it is likely that Google uses a variation of it but they tell us that exactly. At any rate, no problem, since this equation is good enough.
In equation, ‘t1 – tn’ are pages linking to page A, ‘C’ is the number of outbound links that a page has and 'd’ 're a damping factor, normally it 0.85.
We can think of a simpler:
The PageRank of a page = 0.15 + 0.85 * (a “portion” the PageRank of every page that links)
“portion” = The linking page's PageRank divided by the number of outgoing links.
A page “vote” an amount of PageRank for each page that links. The amount of PageRank that it has to vote is somewhat smaller than its own value of Pagerank (its own value * 0.85). This value is shared equally between all the pages that it links.
From here, we can conclude that a link from a page with PR4 and 5 outbound links is worth more than a link from a page with PR8 and 100 outgoing links. The PageRank of a page that links to yours is important but the number of links on that page is also important. The more links you have on a page, less PageRank value your page will receive this.
If the PageRank value differences between PR1, PR2, … PR10 were equal, then this conclusion is supported, but many people believe that the values between PR1 and PR10 (maximum) are fixed on a logarithmic scale, and there are good reasons to believe. Nobody outside Google knows for sure one way or another, but the likelihood that the scale is logarithmic are high, or similar. If so, means it takes much more PageRank for a page to the next PageRank level that it took to pass the previous level. This result reverses the previous conclusion, a link from a PR8 page that has lots of outbound links is far more important than a link from a PR4 page that has a few outgoing links.
Whatever the scale using Google, we can be sure of one thing. A link site increases our site's PageRank. Simply, do not forget to avoid links from link farms.
Keep in mind that when a page votes its PageRank value to other pages, its own PageRank is not reduced by the value you are voting. The voting page does not lose its PageRank and stays with nothing. There is a transfer of PageRank. It is simply a vote according to the value of PageRank of the page. It's like a meeting of shareholders, where each shareholder votes according to the number of shares held, but the actions themselves not lost. Even so, pages lose some PageRank indirectly, as we shall see later.
Ok far? Well. Now we will see how the calculations are actually made
For calculating a page, su existing PageRank (if any) is completely abandoned and a new calculation is done where the page relies solely on the PageRank “voted” for it by its current inbound links, which may have changed since the last time you calculated the PageRank.
The equation shows clearly how comes the PageRank of a page. But what is not immediately obvious is that it can work if the calculation is done only once. Suppose we have 2 pages, And the B, each linked to the other, and neither have other links. This is what happens:
Step 1: Calculate the PageRank of page A with the value of its inbound links.
Page A now has a new PageRank value. In the calculation we used the value of the inbound link from page B. But page B has an inbound link (Page A) and its new PageRank value has not yet been worked, so the new value of PageRank of page A is based on inaccurate data and therefore can not be accurate.
Step2: Calculate page B's PageRank to the value of your inbound links.
Page B has a new PageRank value, but can not be accurate because the calculation used the new PageRank value of the inbound link from page A, which is imprecise.
It is a situation “Caught 2 a 2″. We can not conclude with the A's PageRank until we know B's PageRank, and we can conclude B's PageRank until we know A's PageRank.
Now that both pages have new PageRank values calculated, could not redo the calculations to arrive at the precise values? No. We can redo the calculations using the new values and get more accurate results, but always be using inaccurate values for the calculations, so the results will always be inaccurate.
The problem is solved by repeating the calculations many times. In each iteration are achieved slightly more accurate results. In fact, is impossible to achieve complete accuracy as the calculations are always based on inaccurate values. Forty or fifty iterations are sufficient to reach a point where more iterations not significantly alter the result. This is precisely what Google does at each update and that is the reason I take so.
One thing to keep in mind is that the results we get from the calculations are proportional. The numbers obtained should be placed on a scale (known only to Google) to know the actual PageRank of each page. Even so, we can not use the calculations to channel the PageRank within a site around its pages as some pages receive a higher proportion of PageRank than others.
Note: You probably come from other explanations of PageRank where the same equation is used but the result of each iteration of the calculation is added to the page's existing PageRank. The new value (result + PageRank existing) is then used when sharing PageRank with other pages. These explanations are wrong for the following reasons:
1. They cite the same equation published, but the change.
PR(A) = (1-d) + d(…..) a PR(A) + (1-d) + d(…..)
It is wrong and unnecessary.
2. We will be looking at how to organize links so that certain pages end up with a larger proportion of the PageRank than other. Adding PageRank page exists at each iteration produces different proportions than when the equation is used as published. Knowing that the sum is not part of the equation published, the results are incorrect and inaccurate ratio.
According to the published equation, the page being calculated starts from scratch in each iteration. It is based solely on its inbound links. The idea of adding the existing PageRank does not do that, therefore the results are incorrect.
Done: A website has a maximum amount of PageRank that is distributed between its pages by internal links.
The maximum PageRank in a site is equivalent to the number of pages on the site * 1. The maximum is increased by inbound links from other websites and decremented by outbound links to other websites. We are talking about the overall PageRank website, not the PageRank of each individual page. You do not need to take my word for it. It can reach the same conclusion using pencil, paper and the equation.
Done: The maximum PageRank in a site at the same time increases the number of pages on the site increases.
The more pages have a website, more PageRank have that site. Once more, using paper, pencil and equation, can reach the same conclusion. Note that the only pages that count are those that Google knows.
Done: Linking poor form, may fail to achieve the highest PageRank of the website, but you can not exceed it.
Paupers links can cause a site does not reach its maximum but no kind of internal link structure will cause the site to exceed its maximum. The only way to increase the maximum is to add more inbound links and / or increasing the number of pages in the website.
Caution: While I thoroughly recommend creating and adding new pages to increase a site's total PageRank so they can be channeled to certain pages, There are some types of pages that should not be added. These pages are identical or very similar and are known as “cookie-cutters” (cookie cutters). Google's considered spam and can trigger an alarm that causes the pages, and possibly the whole website, be penalized. Pages full of good content are ideally.
What can this PageRank hacer 'global'?
Let's look at some examples of calculations to see how it can be manipulated the PageRank of a website , but before that, I need to point out that a page will be included in Google only if one or more pages of the network links. According to Google. If a page is not in the Google index, any links from it can be included in the calculations.
For the examples, we will ignore this, mainly because the type documents “PageRank al detalle” ignore this in the calculations, and would probably be confusing when comparing documents. La calculator operates in modes: Simple y Real. In Simple mode, assumed in the calculations that all pages are indexed in Google, are linked or not from other pages. In Real mode, ignoring the pages that are not linked. These examples show the results of calculations in Simple mode.
Consider a website 3 pages (The pages, B to C) unlinked from abroad. Asignaremos every page un PageRank initial and 1, although there is no difference in start on each page 1, 0 o 99. Apart from a few millionths of a PageRank point, after many iterations the end result is always the same. Starting 1 requires fewer iterations to converge on a PageRank suitable result starting from 0 or any other number. You probably want to use pencil and paper to keep the calculations, Also we can continue with the calculator.
The web site's maximum PageRank is the amount of PageRank in the site. In this case, have 3 therefore pages maximum is 3.
For the time being, any pages connected to another. If the calculation is performed once for each page, find that each one ends with a PageRank of 0.15. No matter how many iterations do, each page will keep 0.15 PageRank. The web site's total PageRank = 0.45, when it could be 3. The website is seriously wasting most of their potential PageRank.
Example1: Start again PR1 assigning to each page. Link page A to page B and run the calculations for each page. We ended up with:
The page = 0.15
Page B = 1
Page C = 0.15
Page A has “voted” the site B and, result, the PageRank of the page B has increased. This is good for page B, but it is only one iteration, we have not taken into account the situation “Caught 2 a 2″. Observe what happens to the numbers after several iterations:
After 100 Iterations are numbers:
The page = 0.15
Page B = 0.2775
Page C = 0.15
Keep painting good for page B but nothing like what I had at first. These numbers are much more realistic. The total PageRank in the site is now 0.5775, slightly better but still a fraction of what could be.
Note: Technically, these particular results are incorrect because of the special treatment that gives Google the links “loose”, but serve to demonstrate a simple calculation.
Example2: Try these links. Link all pages to all pages. Each page starts with PR1. This produces:
The page = 1
Page B = 1
Page C = 1
Now that we have reached the maximum. NO need to worry about how many iterations do, Always end each page with PR1. The same results occur in a hoop linking. Example: A to B, B to C, C to D. View this on the calculator.
This has demonstrated that, linked poor, is quite easy to waste PageRank and linking of good ways we can get the full potential of the website. But we do not want all pages have the same importance. We want one or more pages are more important than others. The type of pages you might want to have more importance could be the index pages, pages main section and any pages that are optimized for certain terms. We just have 3 pages, hence, we will channel the PageRank to the index page, page A. Will serve to show the idea of channeling.
Example3: Try this. Link page A to B and C. Also link the pages B and C to A. Starting with PR1 all, after 1 iteration results are:
The page = 1.85
Page B = 0.575
Page C = 0.575
And after 100 iterations, the results are:
The page = 1.459459
Page B = 0.7702703
Page C = 0.7702703
In both cases the total PageRank in the site is 3 (maximum) so do not waste anything. Also in both cases can see page A has a much greater proportion of the other PageRank 2. This is because pages B and C are passing PageRank to A and nothing to the other pages. We have channeled much of PageRank to where we wanted.
Example 4: Finally, save the links above and add a link to page C to page B. Start again with PR1 on each page. After 1 iteration:
The page = 1.425
Page B = 1
Page C = 0.575
Comparing the numbers of the first iteration in the above example, page A has lost some PageRank, page B has gained some and page C stayed the same. Page C now shares its “vote2 between A and B. Previously A received it all. Why page A has lost and page B has gained. And after 100 iterations:
The page = 1.298245
Page B = 0.9999999
Page C = 0.7017543
Seeing this result, page C has lost a little PageRank because now shared its vote between A and B, instead of all the dárselo, A has less to give to C in the A –> C link. For that reason, adding an extra link on a page causes the page to lose PageRank indirectly if any of the pages to which it links back link. If the page that links to not return the link, then not lose PageRank. To make it more complicated, if the link is returned even indirectly (via a page that links to another page that links to another page, etc), page PageRank lose some. This is not very important with internal links, but can be a problem when we join offsite web pages.
Example 5: New Pages.
Adding new pages to a site is an important way to increase the total PageRank of a website because every new page added an average of 1 the total. Once the new pages have been added, its new PageRank can be channeled to important pages. We will use the calculator to demonstrate this.
Add 3 new pages to Example 3 [see]. Three new pages but do nothing for us yet. The small increase in the Total, and the new PageRank of the pages (0.15), are realistic in check as Podremos. So link them to the site.
Link each of the new pages to the important, The main [see]. Note that the Total PageRank has been folded, of 3 (no new pages) a 6. Note also that the PageRank of page A has been almost doubled.
There is something wrong with this model. The new pages are orphans. They can not be indexed in Google, so do not add any PageRank to the site and will not pass any PageRank to page A. Each needs to be linked from at least one other page. If page A is the important page, the best page to put the links is, surprisingly, page A [see]. You can test the links but, from the viewpoint of the page A, there's no better place to put the links.
Not a good idea for a page link to a large number of pages, so if you are adding many new pages, hand out the links for other pages. Probably more of an important page on a website, thus, usually appropriate to share the links to and from the new pages. You can use the calculator to experiment with mini-models of a site to find a combination of links that produce the best results for its important pages.
Summary of Examples:
You can see that, organizing the internal links, is possible to channel the PageRank to selected pages website. Internal links can be arranged to adapt the PageRank of the website to your needs, but only useful if Google knows the pages, for that reason, make sure that Google finds.
Incoming and outgoing links:
You can give examples of this but it is probably clearer to read about it (below) and 'play’ with them in the Calculator.
When a page has many links to another page, include all?
Example, if page A links once to page B and 3 page times with C, page C receives 3/4 A distributable PageRank?
The concept of PageRank is that a page votes for one or more pages. Nothing is said in the original PageRank document about voting more than once to a page. The idea seems to be against the concept of PageRank and certainly would be open manipulations with unrealistic proportions of votes. Example, if an output link, or a link to a page very unimportant, necessary, adds a lot of links to important page to minimize the effect.
Since it is very unlikely to receive a definitive answer from Google, is reasonable to assume that a page can vote once for another page, and that additional votes for the same page are not counted.
When a page links to itself, count the link?
Once more, the concept is that pages vote for other pages. Nothing is said in the original document about pages being voted to themselves. The idea seems to be against the concept and, also, would be a way of manipulating the results. For these reasons, is reasonable to assume that a page can not be voted itself and that these links are not counted.
“The dangling bonds are simply links that point to a page that has no outgoing links. They affect the model because it is not clear where their weight should be distributed, and a large number of them. Often these dangling bonds are pages that we have not downloaded yet……. Because dangling bonds do not affect the ranking of any other page directly, we simply delete the system until the PageRank of all pages is calculated. After all been calculated PageRank, pages can be added again without significantly affecting things.” Excerpt original PageRank by the founders of Google, Sergey Brin y Lawrence Page.
A dangling link is a link to a page that has no outgoing links, or a link to a page that Google has not indexed. In both cases Google removes links just to start the calculations and reinstates just after finishing the calculations. Thereby, the dangling bonds minimally affect the PageRank of other pages.
The results shown in Example 1 (right diagram) are wrong because page B has no outgoing links, for only, a link to the page A to B is hanging and will be eliminated from the calculations. The calculation results show the three pages with 0.15.
You may link to pages that have no outgoing links without losing PageRank suits page functionality but it would be a waste of potential PageRank. Take a look at this example. The potential of the website is 5 because it has 5 pages, but linked page E, the website has only 4.15.
Link page A to page E and click Calculate. Note that the total has dropped considerably website. But, as the new link is hanging and will be eliminated from the calculations, we can ignore the new total and assume 4.15 and certain. This is functionally useful effect of dangling bonds. No loss of PageRank.
However, some potential is still losing, so E page link to page A and click “Calculate”. Now we have the maximum PageRank that is possible with 5 pages. Nothing is wasted.
While it may be good, functionally speaking, link pages in the web site without the link to either send back, is bad for the PageRank. PageRank is a waste of unnecessary and unjustified, so always be sure that each page has an outgoing link to another page on the website.
Inbound links (links to the website from outside) are a way to increase the total PageRank of a website. The other is to add more pages. Do not worry about what the source of links. Google recognizes that a webmaster has no control over websites will link, so that websites are not penalized for inbound links. There is one exception to this rule but it is rare and does not concern this article. It's not something that a webmaster can accidentally do.
The PageRank of the page linking to us is important, but also the number of outgoing links from that page. E.g., if the link to your website is the only one of a page that has a low PR2, You receive an injection of 0.15 + 0.85(2/1) = /1.85 and(No Website, while a link from a page with PR8 containing 99 links will increase your PageRank 0.15+0.85(7/100) = 0.2095. Clearly, the link of the page with PR2 is much better. The are so? Look here for a possible reason that this is not true.
Once the PageRank is injected into your website, the calculations are redone and PageRank of each page changes. Depending on the structure of internal links, some pages PageRank increases and other remains unchanged but none is lost PageRank.
It is beneficial to have inbound links to pages that are being channeled PageRank. A PageRank injection to any page will be spread throughout the web site through internal links. Important pages receive an increase, but not so much as linked directly. The page that receives the inbound link is the most gain obtained.
We consider our website as a small autonomous network pages. When we calculate PageRank, we are serving our small network. If we make a link to another site, we lose some of our network's PageRank, and if we receive a link, our network PageRank is increased. But this is not so. For the calculation of PageRank, there is only one network, any page that Google has in its index. Any iteration of the calculation is made in the whole network and not on individual sites.
The entire network is interconnected, and each link of each page plays a role in each iteration of the calculations, is impossible for us to calculate the effect of inbound links to our website with a realistic accuracy.
Outgoing links are PageRank total drain a website. They “drip” e PageRank. To counteract the drain, ensure that these links are reciprocal. For the PageRank of the pages of each end of each external link, and the number of outgoing links from those pages, reciprocal links can gain or lose PageRank. Need to be careful when choosing where to exchange links.
When PageRank is lost on a website via a link to another website, all pages in the internal link structure are affected. (This is not always displayed after 1 iteration). The page makes a difference links between pages that suffer greater loss. Without a program to perform the calculations on a specific link structure, is very difficult to decide the right page to link, but is generally less PageRank page.
El atributo ‘action’ of a form need not be a path to a forms processor. You can point to any html page on any other website. Try.