I am a doctor with 30 years of experience with computer applications for medical education and research and I have been applying the principles of evidence based clinical practice to SEO.
Easily verifiable evidence that the top factor in the Google positioning algorithm is HomePage PageRank has been published. The second factor is a hidden boost that Google gives to the effective PageRank of HomePages competing for keywords.
There are three main benefits when you understand the top two factors used by Google:
Firstly, it becomes possible to identify those keywords for which a website can achieve top page positioning on Google and those that are out of range. This will prevent expenditure of precious resources chasing rainbows.
Secondly, by targeting keywords that are in range, your website will be able to steadily increase its authority and ever more desirable keywords will come into range.
Finally, you will understand why there can be no magic bullet that will catapult any website to top page positioning for all the keywords it desires. You will learn to be more than sceptical with anybody who makes such incredulous claims.
A keyword tool - http://www.KeywordSEOPro.com - based on the above research findings has been developed. Those who check out my theory welcome a program that automates the simple but time consuming calculations.
My website, http://www.firstwebsitedesign.com, provides valuable information for beginners and intermediates in website design and search engine optimization.