Hello,simple question:

searching on http://www.yahoo.it for villa matrimonio bologna I noticed Yahoo shows different results. You need to retry few times to get this done maybe exiting the browser and openeing it again, or maybe searching once and then clearing browser cookies and then search again (it's even easier to test if you use two different browsers at the same time to search for the same phrase).

Anyway in order to reproduce this easily I write down here the query shown in the address bar after the search, so you can just click on these to see the results shown by entering these query:

• http://it.search.yahoo.com/search;_ylt=AirvLYKvBMPP_6MpAmONN14brK5_?vc=&p=villa+matrimonio+bologna&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-709

• http://it.search.yahoo.com/search;_ylt=AirvLYKvBMPP_6MpAmONN14brK5_?vc=&p=villa+matrimonio+bologna&toggle=1&cop=mss&ei=UTF-8&fr=sfp

Note the last parameter fr is different, but it's Yahoo that set it (not me), I don't even know what it means.

You can see in the search box that the searched phrase is IDENTICAL in both cases.

So why Yahoo is giving out different results on same search phrase?

I used the same browser and performed the test in few minutes by simply trying more than once.

You may also notice that the number of results returned (written on the left side of the page) is different, for the 1st search it returns 274K results, for the 2nd one 5.38M results.

Actually you might think that this is just an error on Yahoo, but it's almost 1 year that while looking once in a while at some websites to see how they are ranking on Yahoo and also Google, I noticed that two searches on the same phrase show up different results even on the same day after few minutes/hours. I couldn't reproduce this behaviour also on Google so I can not say for sure, but since it seems to me it happened sometimes I was wondering if anyone of you noticed it too.

Do you know if this is the normal behaviour of search engines? Because if it's normal (and it's just me that noticed it only now) I wonder how do you understand how well a site is ranking on a search engine, you could even see one of your customer's website ranking differently compared to what your customer sees on his PC.