| In the SEO arena there is a lot of focus on PageRank as an indicator of a domain's SEO value. Although it is probably one of the most important factors in a domain's worth in the eyes of Google, there are a few things that should be mentioned.
First of all, for anybody who doesn't know what PageRank is - it is a value used by Google to determine how important a domain is based on analysis of link on the internet. Pages that don't have any PageRank are often symbolised as having N/A PageRank.Google gives each page on the internet a score and when one web page links to another it passes some value onto the page it is linking to. Google PageRank has 11 scores, between 1 and 10. The higher the PageRank, the more likely Google is to trust it. This is true for both external and internal hyperlinks.
So, if a web page has 4 PageRank 4 and 3 PageRank 3 links pointing at it, it will probably be give a PageRank of 4. The higher the PageRank of pages linking to a given page, the higher its PageRank is likely to be. The sheer quantity of links does not help to increase PageRank. In addition, web pages that have a lot of low PageRank and PageRank N/A hyperlinks pointing to them can have their PageRank reduced as a result. PageRank is generally not assigned to a page higher than the pages that link to it. Probably the most important factor in the distribution of PageRank to a web page is the PageRank of the web pages linking to it. A site can have a high PageRank with relatively few links pointing to it if those links are of a high PageRank.
Some people suggest that the text content of a page affects PageRank assignment, but this doesn't seem to be the case. There is no evidence that text affects PageRank other than pages that have been spammed often have their PageRank removed.
When it come to sub-pages, the time Google has known about them is a factor in PageRank assignment. When new sites first get assigned PageRank their sub-pages often remain without any PageRank. In general, sub-pages are a little slow to get give PageRank. Google is generally less trusting of sub-pages unless they belong to a trusted domain. In particular sites with a lot of sub-pages and even more so sites that link to a lot of internal pages (like directories) can struggle to pass their PageRank to internal pages.
The architecture of the site has a major role to play in the distribution of PageRank. Google uses what is known as block level analysis to pick apart web pages. They use their vast knowledge of the architecture of the web to decide what links on a page are probably the most important and the pages these links point to are more likely to be assigned PageRank.
Google can and do manipulate websites' PageRank. This is generally as a penalty for sites that have used unhonest practices. This can often cause all the site's sub-pages to loose their PageRank. It has also been claimed that in the past Google has made mistakes in PageRank assignment.
Finally, the PageRank of a web page may change even though there has been no change in the links pointing to that page. This is either due to changes in the structure of links between all websites or adjustments made by Google.
Sky Alfaro is an SEO consultant with the SEM Labs SEO Agency where she helps small to medium sized companies with search engine marketing training. |
