How often does Google change algorithms?

I've read that Google changes algorithms to discourage black hat SEO. How often do these changes happen and how would people find out?

Thanks

Ruben

 

i think there are no one knows when google change the algorithms but I can say recently google very often change the algorithms

 

I think they just come up with new ways to weed out backhat SEO.

 

As per my knowledge, google updates it's algorithm for every three months. Google recently updated it's algorithm on 2nd April 2009.

 

Google updates their algo very frequently... way more often than every 3 months. They typically publish PR updates every 3-4 months but that is totally different from changes to their indexing and ranking algorithms.

 

Hi,
Each month, the search positioning rankings change as a result of the latest Google algorithm updates. Google Algorithm is discussed by Search Engine Optimization (SEO) experts. Google Algorithm is a mathematical formula that seems to look fairly simple to understand. Google algorithm calculates what we call Google Page Rank. By showing how the algorithm code calculates a page rank allows use to explain how we believe the Google Page Rank works.

 

It changes every few months. To be a webmaster, you have to follow the change.

 

I don't know but I think every update Google change their Algorithm.

 

No one knows how often Google updates its algorithm. Google always wants to keep ahead of SEO tactics.

 

google update at regular 2 month interval, u can find out same from your site behavior

 

I think the changes might be also based on user behaviour.

 

There's no specific time .But very frequently Google change their algorithm.

 

Only Google will knows about their Algo changes. You should always keep eye on discussion forums like DP to get updated.

 

Matt Cutts stated a little while back in one of his videos that Google made 400+ changes to the algo in the previous year.

the big ones come a little less often but there have been a few lately.

this permanently ongoing thread is the best place I know to track and discuss changes people are seeing, it gets very busy when there''s anything much going on. we also outlined the latest (April 09) changes here

 

google has 2 types of change PR updates which happen every 3 months and serp algoritm update which happen when they need it ( like a couple of days ago to fight spam)

 

This is similar to what I had heard as well... basically, that they tweak their algo almost daily or every couple of days. For some reason the number 183 times sticks in my mind for last year alone. But I can't say for sure and don't remember the source... Could have been Cutts or some other Google engineer mentioning it in passing at a lunch table at this past Vegas Pubcon in Nov 2008, but again I really don't recall where I heard it.

 

They change their algorithms every time they see a problem with their current algorithms. That could be ANY time period from a few minutes to a few months.

 

I read an article that suggested Google made 450 tweaks to their algorithms in 2008. So as a rule of thumb you can count on some kind of change daily!

The battle against spam is ongoing and change is ongoing.

 

they dont, they change it every time they think they can make the search results better, theres a difference.

 

No difference.