"Searches related to:" - Where are these from?

[foolsgold]

These are at the bottom of the natural searches and there are usually 8 results and these are 'fixed' to be the same on all search pages.

Searches related to:

Does anyone know where these results are coming from?

[tedster]

I've been supposing that it comes from Google's record of frequent searches, combined with some semantic processing -- but that's guesswork. Some searches also show a simlarly positioned feature: "Refine your Search". I also would like to know the difference between these two, and how each one comes about -- especially since I have only one guess but two related things to understand ;)

[annej]

This is a great topic. I even wondered if it might be based on earlier searches by the person searching. I had web history turned on for a while but that was quite a while back. Am I getting too paranoid?

[Robert Charlton]

The related-to searches at the bottom...

I've been supposing that it comes from Google's record of frequent searches, combined with some semantic processing -- but that's guesswork.

I essentially concur... seems to be a combination of various sets of results you'd get from Google Suggest [google.com], which in the past, I've observed, does appear to suggest searches in order of search frequency. (Note that Suggest also lists the number of pages returned, which does not necessarily correlate with search frequency).

Search refinements...

Some searches also show a simlarly positioned feature: "Refine your Search". I also would like to know the difference between these two, and how each one comes about -- especially since I have only one guess but two related things to understand ;)

I'm guessing here too, but I've associated these with the medical refinements, which came out of Google Co-Op [google.com]. Co-Op has gone through a bunch of changes since these, but, as I understand it, in all its forms, it's been using a combination of tagging seeded by "experts" and measures of social acceptance of the results.

Some earlier thoughts I had on Co-Op...

[webmasterworld.com...]

...Google has done this with Google Co-Op, where they're using humans with "specific expertise" to suggest and tag authoritative sites. Other humans subscribe, and perhaps their usage patterns become a measure of quality. When results become good enough, they appear on the main page....

And some observations on the refinements...

[webmasterworld.com...]

Google has been experimenting for quite some time with various methods of grouping serps results by category. These usually kick in on extremely general searches, where it's likely that modifiers will be necessary to produce results that will satisfy the user....

If my guesses are right, the "related searches" come from search-frequency info, and the "refinements" come from social seeding, tagging, and measures of user satisfaction.

[Robert Charlton]

A PS to the above...

The Refinements appear to be applied uniformly to categories of similar things... ie, medical conditions get a set of refinements... cities get a set of refinements.... And the refinements are categories themselves. They don't behave as if they're additional words just tacked onto a search.

The Related Searches, on the other hand, are frequently searched word combinations.