I expect you will receive a response from the Moz team by Monday on your other open Q&A / ticket. The person who answers that question may be able to answer this one, or pass your inquiry along to someone who does.

I believe reverse-engineering the PA / DA is pretty straight forward. To the best of my knowledge, the following is true regarding the calculation:

• It is 100% based solely on link data

• OSE is the single data source for the calculation

• there are only a few factors: the PA/DA of any linking pages/sites, the number of links on the page providing the link, the number of links being received by the page/site.

• typical factors known to be used in PR such as relevancy, link location, etc. are not factors in PA/DA

• spam factors are not considered in PA/DA

To the best of my knowledge the above is correct. Only a SEOmoz employee could possibly confirm and I am unsure on their NDA requirements. I would expect their formula is proprietary.

With the above understood, a DA of 30 represents the number and quality of links received for the website. The same applies to PA.

A site with DA of 29: http://www.cheshirecatnarrowboats.co.uk/

A page with PA of 31 http://www.shmoop.com/alice-in-wonderland-looking-glass/cheshire-cat.html

I recognize you are likely aware of the above information and seeking something deeper. I am sharing this information in case it is helpful.

I can't say exactly what formula is used for PA/DA, but it is designed to emulate PR. Either way, as long as you include PR you already have a logarithmic metric.

Whatever system you use will be challenging. Why?

• Google includes 200+ metrics to determine search result positioning

• Google adjusts search results based on numerous personal factors including location, browsing history, etc

• It is pretty safe to say Google's algorithm includes metrics which are linear, exponential and logarithmic

With dozens of various tools on the market designed to analyze keywords, why not chose to utilize an existing tool which is professionally developed and maintained for this purpose?

I can't agree with Anirban's suggestion. A 301 redirect would be the superior solution.

Your site is published under multiple domains:

http://aa-rental.com/

http://www.aa-rental.com/

Notice both of the above links brings up the same content on your site but under different URLs. That should not happen.

http://seomoz.org/q/root-domain-or-sub-domain

Notice if you try the above link for this Q&A response, the URL is changed to add the "www." subdomain. That is what should happen if you have a site presented on the www subdomain.

You need to decide how you wish to present your site, with or without the www subdomain. Once that decision has been made, it needs to be enforced with server side code. Once that issue is resolved, the particular crawl issue you mentioned should be resolved.

A great reminder for us all. Thanks for sharing Dana. #RCS