How can I fix this pagination formula?

[msafi]

The CMS I'm using paginates user comments. I set it to show 5 comments per page with the latest comments on top. And I have 11 comments. And show the last page first.

Currently, this is what the CMS does:

Page 1 shows comments 5, 4, 3, 2, 1
Page 2 shows comments 10, 9, 8, 7, 6
Page 3 shows comment 11

Here's the problem, since I told the CMS that I want to show latest comments first and last page first, it shows page 3 first, so the user only sees 11. To see the rest of the comment, user has to click on "See older comments ->" to go to page 2, etc.

The behavior I'd rather have is this:

Page 1 shows comment 1
Page 2 shows comments 6, 5, 4, 3, 2
Page 3 shows comments 11, 10, 9, 8, 7

Here's the code that needs to be fixed: [pastebin.mozilla.org...]

[g1smd]

With your new scheme think about what is indexed compared to what is really on the page if you add some comments. User will arrive at a page based on what they saw in the SERPs, but that content will no longer be on THAT page.

Think about how, after adding 5 comments, the new page two is a duplicate of the old page one and the new page three is a duplicate of the old page two, and previously that content was originally on page one. See also that there are up to 5 sets of these duplicate pages (because there are 5 comments per page). Extend this over a long period of time to see how much of an indexing mess this creates.

[msafi]

g1smd, Page 3, which is the default first page that the user sees, does not have its own URL. It shares the same URL with the "content" page. That is: http://example.com/foobar/ shows Page 3 of comments. Page 2 of comments is located at http://example.com/foo/comments-page-2/ and Page 1 of comments is at http://example.com/foo/comments-page-1/. Newer comments push older comments down.

There are no duplicate content issues here. Even if there were, I'd be able to handle it with rel="canonical" no problem. I also link to sitemap.xml from robots.txt to tell engines what the main pages are. I don't include comments pages there.

Thanks for your concern.

I'd really love some help with the formulas!

[g1smd]

To be clear, you're saying that comments 1 to 5 are always on the page that has "page-1" as its URL?

If so, then that's a good thing.

[msafi]

No, comments 1-5 will move up the pages as more comments come in. At first, comments 1-5 will be on http://example.com/foo/. When 5 more comments come in, 1-5 will be on page-1. After yet another five comments, they'll move to page-2, etc...But that won't cause any SEO damage. There will be no duplicate content. The engines will just have to update their data -- like they have to do with all other dynamic sites...

EDIT: No I think I'm wrong here. They'll remain on page-1. Newer comments will go to page-2 and page-2 will be displayed before page-1 in pagination.

[edited by: msafi at 5:58 pm (utc) on Apr 10, 2011]

[g1smd]

Yes, and that is the point. The same content keeps swapping to a different URL, and because of that some content will be indexed on multiple page URLs and other content will not be indexed at all when you take a snapshot at any particular point in time.

This is a fundamental and damaging flaw in site design, yet one that people shrug off without looking in depth at the consequences. It is quite possible to design a dynamic site where the whole site content does not swap to new URLs every time something else is added.

EDIT: If comments 1 to 5 are always found at the URL "page-1", with the newest content on the highest numbered page URLs, the problem is fixed.

[msafi]

Please check my edit. Also, I'm sorry but even if the comments kept moving to different URLs, I wouldn't consider this to be an issue.