Duplicate Content Error because of passed through variables

[CTSupp]

Hi everyone...

When getting our weekly crawl of our site from SEOMoz, we are getting errors for duplicate content. We generate pages dynamically based on variables we carry through the URL's, like:

http://www.example123.com/fun/life/1084.php
http://www.example123.com/fun/life/1084.php?top=true

ie, ?top=true is the variable being passed through.

We are a large site (approx 7000 pages) so obviously we are getting many of these duplicate content errors in the SEOMoz report.

Question: Are the search engines also penalizing for duplicate content based on variables being passed through?

Thanks!

[Fatwallet]

you need to fix it. it's likely not drawing a penalty or anything severe, but cleaning up will certainly help concentrate your pagerank and rid of any dilution and confusion.

you should treat each page to a canonical tag referencing the non parametered url.

you can also use google webmaster tools to tell google to ignore the top= parameter, but the canonical tag is your best option.

[lordmoose8545]

In our experience it does not help the end goal. And we have comprehensively got rid of all of these duplicates and Google seems to have liked?????? it????....

We were lagging behind one of our competitors with a much weaker site now we are in front and #1 Page #1

So I would say that it has some benefit to clearing this up. But overall it is a small amount.