Seeing Different Results in SERP After Hitting Previous Button

[gouri]

I have noticed this recently and I was wondering if anyone might be able to tell me what it means.

Say I am doing a search for widgets and I am on page 2 of the SERP and expect to see a site on widgets. Maybe in position 20. I don't see it. Then I go to the third page and hit previous. When I now look the site that I have seen in position 20 is now there.

I have seen this happen a number of times and I am not sure how that is happening.

[tedster]

I've never seen the results change when clicking a link on the Google results page. Repeating a query, ues, but not just clicking. I wonder if you may have been routed to a different data center by their load-balancing software.

[gouri]

Thanks for responding. That is a possibilty but I wanted to mention that I have seen this happen a number of times.

Also, can you please tell me what ues stands for?

[caribguy]

That should not happen unless your browser is set to always load a fresh copy of the page time rather than pulling it from its cache.

... I think that was meant to say "yes" :)

[tedster]

caribguy is right - it was a fat fingered typo, gouri.

[JoeSinkwitz]

This has been happening for over a year; gouri isn't hallucinating. This is most obvious for a site that is #10 in one DC and #11 in another, with the load balancing bouncing it back and forth.

[gouri]

Sorry Ted. I just didn't realize you were trying to say yes.

Does this mean when I hit previous Google likes to get returns from a different data center? I didn't mention this but I see it more for certain terms than others. For some terms, what you see on the previous page when you go back to it doesn't change.

Maybe this might help to analyze this more.

[gouri]

Joe,

Thanks for that post. What you say is a sharp observation. I am trying to understand this concept.

[Receptional Andy]

gouri: when you search, the results are potentially returned from one of a large number of data centres hosting Google results. Often, those data centres have different results on them, as a result of algorithmic changes, or a different index. A visit to Google.com can be routed to a great variety of different destinations.

Any time your browser doesn't cache a previously visited page, you will potentially see different results. I imagine Google aim to deliver the same data centre for people clicking through search results, but I frequently get different results when navigating through SERPs.

Watching individual data centres is something that a lot of SEOs do, in order to get a handle on algorithmic varations that may be in place at any given time. There are lots of topics on the site about Google's infrastructure:

[data centers site:webmasterworld.com/google] [google.com]

[gouri]

Thanks, Andy.

I will try to understand a little more about data centres than I currently do. I think it would be good to know.

Also, thanks for the link.

[Receptional Andy]

I've enjoyed the reading about data centers myself. A handful of those relevant to this thread include:

• Google's Data Center Info, Estimates At "Far Beyond 200,000" Servers [webmasterworld.com]
  
• Current State of Google Data Center Technology [webmasterworld.com]
  
• How Do I Know Which Google Center I am Looking At [webmasterworld.com]
  [/url]
  

[edited by: Receptional_Andy at 12:15 am (utc) on Nov. 19, 2008]

[caribguy]

Thanks RA for pointing out those enlightening threads. A reminder to never assume anything and to keep learning....

[Jane_Doe]

I have seen this happen a number of times and I am not sure how that is happening.

I believe it is the start of personalized search. In my experience I think sometimes they show you sites that you have clicked on in the past higher than those sites would normally be in the rankings if you had not clicked on them. Then it changes when you use the back button.

So if you want to find out your real placement for your own sites, sometimes you have to go to page 2 or 3 and then scroll back and then you get the more generic results.

I do not think this is due to typos as I have noticed this pattern on many occasions myself. I have done a little bit of testing looking at the results from 2 different PCs with different IP addresses, and personally my guess would be that this specific behavior is due to past clicking events, though hitting different servers can also give different results, too. But I think this specific pattern described by the OP is due to some form of personalized search.

[edited by: Jane_Doe at 6:37 am (utc) on Nov. 19, 2008]

[Dave_Hybrid]

Yep, seen this before and recently.

Search for a KW and nothing for 1st and 2nd page, then hit previous to go back to 1st page and there I am.