Google updates - In the past, Google updated its search algorithm in large jumps periodically, resulting in
massive changes in
PageRank and in positioning of
pages in search results for different
keywords.
Most of the changes appear to be related to protecting the algorithm against spamdexing and blackhat techniques or
to screening to downgrade or eliminate sites or pages engaged in spamdexing or in finer
tuning of pages that are supposed to be related to a keyword. After one update, reductions of as much as 50%
in the number of pages indexed by Google for a keyword could be
observed. Most of these updates were not announced by Google, but are inferred from the massive changes in
positioning and PageRank. Very often the massive changes in positioning or PageRank would gradually be reversed over
the course of a few weeks, so that adversely affected pages or sites regained their previous position.
Recently, Google has evidently shifted to a more gradual and continuous update policy, so
that major changes are not as noticeable.
These updates should not be confused with the Google Dance, the periodic updating of individual servers with new
information about backlinks and page content, which did not affect the algorithm. An "update" that is listed as
occurring only a few days after another update is probably just a data update and not an algorithm change.
Some important updates:
Allegra Update
- Update of circa February 2005, that may have involved an attempt to implement Latent Semantic Indexing (association of
words that appear frequently together) as well as allowing
many sites to emerge from the Google Sandbox. Website owners
complained that their sites were frequently not top listed when they searched for their own domain
name or company name.
Bourbon - May-June of 2005. This update was done in stages and may have involved any and
all of the following, designed to "improve search quality" -
(see Google Quality Rater Secrets).
Duplicate Content - Including the same or very similar content on more than one page, even on different
domains/subdomains.
Non-thematic Linking - Having links to pages which contain content irrelevant to the source page's subject matter,
Low Quality Reciprocal Links - Links from "bad neighborhoods". (link farms and poorly rated sites).
Fraternal Linking - Creating a network of sites, which all link back to the same "master" site in an effort to boost
the master site's ranking. (How is this to be distinguished from a true Hub or Hilltop Search
algorithm?)
Above is from The Google Bourbon Update
Florida - November 2003. At least one part of the update introduced filters for over-optimization. Initially,
the filtering was so severe that most of the relevant pages that were left in the top results were non-commercial. See
here for a
detailed discussion that attributes the changes to anti-spamming protection.
See here for a detailed discussion that attributes the
changes to use of an expert "Hilltop algorithm".
The Guardian newspaper, a "reliable" source of disinformation,
wrongly insisted that
the update occurred in 2004.
Jagger - September - November 2005. Jagger ("Hunter" in German) was given its name by Brett Tabke of
Webmasterworld. It was evidently a Google update that primarily affected PageRank.
Additional Updates - Here are some tables of various updates, some of them unnamed but with fairly profound effects:
From Webmaster World's Brett Tabke (2003) we have this table that also has (in the original) a column showing the
phase of the moon. It is probably not possible to determine the precise time of an update with certainty because they
are implemented on several Data Center servers at different times and may take place in stages. The actual times and
dates are approximate, and some updates that are named separately are really changes that belong to one update:
Google Update History
From seolog we get this information about
updates related to pagerank and backlinks, some of which may
simply be massive integration of new backlink data - a quantitative change, and not an algorithmic change.
2008 Google Backlink and Pagerank Updates
Jan 11 - Backlinks and PageRank
Feb. 26 - Backlinks and PageRank
July 26 - PageRank (Note - this is verified, as around this
time Google announced that it is restoring PageRank to a number of sites that had been penalized by some earlier
changes).
2007 Google Backlink and Pagerank Updates
Jan 10 - Backlinks and PageRank
Jan 14 - PageRank
March 22 - Backlinks
April 28 - Backlinks and PageRank
April 30 - PageRank
October 25-27 PageRank
2006
Google Backlink and Pagerank Updates
Feb. 18 - Backlinks and PageRank
Mar. 4
- Backlinks
April 4-
PageRank
July 13-14:
Backlinks and PageRank
Sept 29: Backlinks and PageRank
It is difficult to validate such data about minor updates if there is no corroboration from others.
Note - Definitions of Search Engine
Optimization terms are based on inferences from common usage and definitions given by other sources. Conclusions about
search engine behavior are based on understanding of the behavior of the most popular search engines. Both are subject
to error or may change. Search engine company management may define or use a term or set or change any policy in any way
they see fit, and may make these definitions and specifications public or not. These decisions and definitions are
beyond our control. Notice: Copyright
All original materials are copyright 2008 by Ami Isseroff. All rights reserved. These pages may not be reproduced in any
form in electronic or printed media without express written permission from the author.
SEO Glossary
