session IDs

[coffeebean]

External links to my page, none of which have querystrings, are redirected to the same URL with a session id appended after the question mark.
All subsequent links on the page have that same session ID in the URL.

GoogleBot may crawl the site one day and index the page with one session ID, and then a few days later get a different session ID for the same page.

The session ID doesn't change any of the content on the page.

Does Google see these as two separate pages? Or does it understand they are the same page treat it as such when calculating backlinks and PR?

[the_nerd]

I would definitely get rid of those session ID and only use them when you really have to track a user session (shopping cart, ...)

Google hates everything that looks like a session-ID because they can be pretty sure they index something that will be gone tomorrow.

[encyclo]

You'll be lucky if Google indexes the URLs at all. You've got two options - either get rid of the session IDs completely, or use cloaking to get rid of them just for the bots.

[coffeebean]

Thanks for the replies. Haven't had trouble getting the pages indexed. The question I'm really after is whether Google is able to apply the effect of backlinks and PR to a page that was given a session ID when the spider found it.

For example, if Google follows 50 external links pointing to a paricular page and gets the same URL with a different session ID appended each time, is it smart enough to figure out that the 50 links actually point to the same page?

And then does it apply those backlinks when judging the value of the page?

[elmarpanzenberger]

Seems like G has some trouble assigning PR. I have quite some pages indexed with ID's (no session ID's tough) - pages where some have the same content but the very most of the others having different content as referring to different widgets - and I have the pages indexed since quite some time.
No PR assignet till now to any of the pages.
New pages are indexed whitin days ...

I forgot: the pages have inbound links but obviously not shown ...

[coffeebean]

Same question applies to inbound links with various tracking params attached, such as?source=xyz.

So every inbound link to a page would have a different tracking variable appended, but they all end up at the same page with the same title, content, etc.

Can Google discern that they all point to the same page even though the URLs are slightly different? Can it apply these as backlinks and do the links transfer PR?

[AprilS]

I agree that you should do what you can to prevent session ids in the URL.

From my own experience, a couple years ago (when we had session ids in the url) I would sit and watch live log files and see Google (and other search engines) indexing the same pages over and over... Though I can't be 100% positive - it seemed like Google saw that I had A LOT of duplicate content on my site.

Regarding passing PR - well, Google doesn't pass PR the same to duplicate pages as it does the original page it found. See the problem? How do you know what page it gave the PR too? Most likely a URL with a session id in it....

Example: Lets say your main page has a PR5 - in a happy world you may like to see "www.domain.com/pageA.html" with a PR4 (or PR5) - but with session ids in place - Google may never see "www.domain.com/pageA.html" - it sees:
www.domain.com/pageA.html?sessionid=GKD998423KFDJ...
www.domain.com/pageA.html?sessionid=9234GKD923OP2...
...etc.

Which page got the PR? Who knows.

What I ended up doing is writing some PHP to detect bots and turn sessions off it was a bot - so there was no chance of a session id being appended to the URL. By doing so I noticed PR being shared throughout our pages A LOT better than before.

I hope that helps in some way. You never know with Google though, someone could have a completely different experience than mine. Google may handle session ids differently now. But, I still think it would be wise to make sure those Session ids from your URLs - There are other bots out there to consider that may not take so kindly to session ids.

[edit_g]

Session ID's are the spawn of the devil - I would bend over backwards to get rid of them.

[coffeebean]

What I ended up doing is writing some PHP to detect bots and turn sessions off it was a bot - so there was no chance of a session id being appended to the URL. By doing so I noticed PR being shared throughout our pages A LOT better than before.

AprilS, did this also result in better rankings or more referrals from Google?

With so many uncertainties about toolbar PR and how many backlinks Google displays vs. how many actually count, it seems rankings and referrals are the truest measure.

Thanks

[AprilS]

Yes, for us - we definately received more traffic from Google due to our pages having a higher ranking. Although I can't be positive, it seemed like our positioning in Google was much better when Google was able to finally index our whole site - perhaps Google puts sites on the back burner while it's trying to deep crawl...and doesn't see the end in site... I don't know.

One thing that is truly unknown is how Google responds to seeing the same page over and over on a site - it may think you have thousands of copies of the same page.

Session ids are very valuable - but either:
1) Don't start sessions until you HAVE to (ie. customer adds something to the shopping cart)
OR
2) Detect search engine bots and don't start sessions at all if it is a bot