The Google Algorithm

The Shroud of Turin, the Marie Celeste, Jack the Ripper, the Bermuda Triangle and ...The Google Algorithm. What do they all have in common? They're all surrounded in mystery and people have spent a lot of time discusssing them, analysing them, debating them.

Whenever Google does it's little dance through the sites I'm working on, a little (big really) part of me thinks "Please don't sink my customer's sites to the bottom of page 65". 

So the people over at Search Engine Journal have put together a list of all of the major  factors in the Google Algorithm. I'm sure Matt Cutts and the other Googleheads are either a little bit annoyed or else they're laughing hard at this attempt. Matt recently said they're are over 200 variables in the Google Algorithm so here's what Search Engine Journal have uncovered so far. This is all speculation though so take it with as many grains of salt as you want.

Domain: 12 factors

1.Domain age;
2.Length of domain registration;
3.Domain registration information hidden/anonymous;
4.Site top level domain (geographical focus, e.g. com versus co.uk);
5.Site top level domain (e.g. .com versus .info);
6.Sub domain or root domain?
7.Domain past records (how often it changed IP);
8.Domain past owners (how often the owner was changed)
9.Keywords in the domain;
10.Domain IP;
11.Domain IP neighbors;
12.Domain external mentions (non-linked)


Server-side: 2 factors

1.Server geographical location;
2.Server reliability / uptime


Architecture: 7 factors

1.URL structure;
2.HTML structure;
3.Semantic structure;
4.Use of external CSS / JS files;
5.Website structure accessibility (use of inaccessible navigation, JavaScript, etc);
6.Use of canonical URLs;
7.“Correct” HTML code (?).


Content: 10 factors

1.Content language
2.Content uniqueness;
3.Amount of content (text versus HTML);
4.Unlinked content density (links versus text);
5.Pure text content ratio (without links, images, code, etc)
6.Content topicality / timeliness (for seasonal searches for example);
7.Semantic information (phrase-based indexing and co-occurring phrase indicators)
8.Content flag for general category (transactional, informational, navigational)
9.Content / market niche
10.Flagged keywords usage (gambling, dating vocabulary)


Internal Cross Linking: 5 factors

1.# of internal links to page;
2.# of internal links to page with identical / targeted anchor text;
3.# of internal links to page from content (instead of navigation bar, breadcrumbs, etc);
4.# of links using “nofollow” attribute; (?)
5.Internal link density,


Website factors: 6 factors

1.Website Robots.txt file content
2.Overall site update frequency;
3.Overall site size (number of pages);
4.Age of the site since it was first discovered by Google
5.XML Sitemap;
6.On-page trust flags


Page-specific factors: 9 factors

1.Page meta Robots tags;
2.Page age;
3.Page freshness (Frequency of edits and
% of page effected (changed) by page edits);
4.Content duplication with other pages of the site (internal duplicate content);
5.Page content reading level; (?)
6.Page load time;
7.Page type (About-us page versus main content page);
8.Page internal popularity (how many internal links it has);
9.Page external popularity (how many external links it has relevant to other pages of this site);


Keywords usage and keyword prominence: 11 factors

1.Keywords in the title of a page;
2.Keywords in the beginning of page title;
3.Keywords in Alt tags;
4.Keywords in anchor text of internal links (internal anchor text);
5.Keywords in anchor text of outbound links (?);
6.Keywords in bold and italic text (?);
7.Keywords in the beginning of the body text;
8.Keywords in body text;
9.Keyword synonyms relating to theme of page/site;
10.Keywords in filenames;
11.Keywords in URL.


Outbound links: 7 factors

1.Number of outbound links (per domain);
2.Number of outbound links (per page);
3.Quality of pages the site links in;
4.Links to bad neighborhoods;
5.Relevancy of outbound links;
6.Links to 404 and other error pages.
7.Links to SEO agencies from clients site


Backlink profile: 20 factors

1.Relevancy of sites linking in;
2.Relevancy of pages linking in;
3.Quality of sites linking in;
4.Quality of web page linking in;
5.Backlinks within network of sites;
6.Co-citations (which sites have similar backlink sources);
7.Link profile diversity:
1.Anchor text diversity;
2.Different IP addresses of linking sites,
3.Geographical diversity,
4.Different TLDs,
5.Topical diversity,
6.Different types of linking sites (logs, directories, etc);
7.Diversity of link placements
8.Authority Link (CNN, BBC, etc) Per Inbound Link
9.Backlinks from bad neighborhoods (absence / presence of backlinks from flagged sites)
10.Reciprocal links ratio (relevant to the overall backlink profile);
11.Social media links ratio (links from social media sites versus overall backlink profile);
12.Backlinks trends and patterns (like sudden spikes or drops of backlink number)
13.Citations in Wikipedia and Dmoz;
14.Backlink profile historical records (ever caught for link buying/selling, etc).


Each Separate Backlink: 6 factors

1.Authority of TLD (.com versus .gov)
2.Authority of a domain linking in
3.Authority of a page linking in
4.Location of a link (footer, navigation, body text)
5.Anchor text of a link (and Alt tag of images linking)
6.Title attribute of a link (?)


Visitor Profile and Behavior: 6 factors

1.Number of visits;
2.Visitors’ demographics;
3.Bounce rate;
4.Visitors’ browsing habits (which other sites they tend to visit)
5.Visiting trends and patterns (like sudden spiked in incoming traffic)
6.How often the listing is clicked within the SERPs (relevant to other listings)


Penalties, Filters and Manipulation: 10 factors

1.Keyword over usage / Keyword stuffing;
2.Link buying flag
3.Link selling flag;
4.Spamming records (comment, forums, other link spam);
5.Cloaking;
6.Hidden Text;
7.Duplicate Content (external duplication)
8.History of past penalties for this domain
9.History of past penalties for this owner
10.History of past penalties for other properties of this owner (?)


More Factors (6):

1.Domain registration with Google Webmaster Tools;
2.Domain presence in Google News;
3.Domain presence in Google Blog Search;
4.Use of the domain in Google AdWords;
5.Use of the domain in Google Analytics;
6.Business name / brand name external mentions.

Anne Smarty, Search Engine Journal - 8th Dec, 2009