Through mybloglog, I came across the smashing magazine community and an article entitled Google PageRank: What Do We Know About It? The article does a very good job of explaining Google PageRank and has 15 points listed under how PageRank works and 13 factors impacting PageRank, but also does a good job of confusing content, quality and ranking factors with items that affect PageRank. I started writing a comment to the post, but quickly realized that it was going to be too long, so I decided to post my comments here:
Summary: How Does PageRank Work?
1. PageRank is only one of numerous methods Google uses to determine a page’s relevance or importance.Google uses over 200 signals to determine a page’s rank within the index. While PageRank is one of the signals, the PageRank calculation itself is not actually used to determine relevance or importance, that’s the job for other parts of the algorithm.
2. Google interprets a link from page A to page B as a vote, by page A, for page B. Google looks not only at the sheer volume of votes; among 100 other aspects it also analyzes the page that casts the vote.In the PageRank calculation there aren’t 100 other aspects, the formula calculates links, that’s it.
3. PageRank is based on incoming links, but not just on the number of them – relevance and quality are important.Relevance and quality are not part of the PageRank calculation. You should try to obtain relevant, quality inbound links to your website, but judging relevance and quality is a content issue.
7. Bad incoming links don’t have impact on Page Rank.The PageRank calculation does not understand what is good and bad, it just calculates a value.
8. Page Rank considers site age, backlink relevancy and backlink duration.Site age and relevancy are ranking factors, although backlink duration is a factor. Just as you can accrue PR through links, it can also be diminished when links are removed.
14. Google calculates pages PRs once every few months.Actually it’s calculated all the time, but what we see in the Google Toolbar (or other online PR tools) is a snapshot in time which is updated every 3 months or so.
Summary: Impact on Google PageRank
1. Frequent content updates don’t improve Page Rank automatically.They don’t update them manually either. Content is not part of the PR calculation.
6. Wikipedia links don’t improve PageRank automatically (update: but pages which extract information from Wikipedia might improve PageRank).Content has nothing to do with the PageRank calculation. Creating great content will earn you links, but referencing Wikipedia here is misleading.
8. Efficient internal onsite linking has an impact on PageRank.I think this needs to be explained further. When developing a website, you should strive to make it search engine friendly and especially Google-friendly by ensuring that your site does a good job of linking to its internal pages. This passes on PageRank from page to page which can help keep internal pages out of the supplemental index. This is important because those pages aren’t spidered anywhere near as frequently and are indexed slightly differently than pages in the main index. So good internal linking has an affect on the PageRank of pages deeper in your site.
9. Related high ranked web-sites count stronger.Ideally you want to acquire links from pages with a high PageRank, but again, the reference to related sites (in terms of topicality) does not have an impact on PageRank. A page with high pagerank may actually pass you less if it has more links, because it’s spread too thin. A page with a PR of 4 could feasibly pass on more PR than a PR8 page depending on the number of links that are on the page.
10. The anchor text of a link is often far more important than whether it’s on a high PageRank pageThis is a ranking factor, not something specific to calculating PageRank. Again, the content or topicality has nothing to do with the PR calculation.
11. Links from and to high quality related sites have an impact on Page Rank.Topicality again, see previous comments.