These are my notes from the online course Introduction to SEO, Coursera (UC Davis).


Google algorithm has over 200 factors and there are updates everyday.

The most influential factors in Google’s search algorithm according to Moz:

  1. Domain level links - quantity and quality of links
  2. Page level links - quantity and quality of links
  3. Page level keyword and content - keyword usage
  4. Page level keyword agnostic - readability, content length, load speed, https
  5. Engagement/traffic Metrics
  6. Domain level brand metrics
  7. Domain level keyword usage
  8. Domain level keyword agnostic
  9. Page level social media metrics

Best practices

  1. Provide high quality content, especially on home page
  2. Obtain high quality links to your site
  3. Make accessible to both users and search engines
  4. Clear hierarchy of content

Types of Factors

  1. On Page Factors
  2. Off Site Factors
  3. Domain Level

Major updates to Google algorithm over the years

  • Nov 2003 Florida (first update to make SEO more complicated) - filtered out spammy SEO: spammy links, keyword stuffing, lack of consistent theme
  • Jan 2004 Austin - filtered out invisible text on page, meta keyword stuffing (meta keywords are no longer a valid signal)
  • Feb 2004 Brandy - LSI (latent semantic indexing), looks to relevant neighborhood of inbound and outbound links
  • June 2005 Personalized - based on personalized search history and proprietary information ( 2007 Universal - search results show images, videos, etc. (more opportunities to get traffic)
  • Feb 2009 Vince - favored big brands over small sites
  • Caffeine - new faster search indexing system that allowed Google to index pages more quickly

  • Panda - updated on a regular basis. Targets thin sites with little organic content or duplicate content (site that first published will rank well). Rewards good site navigation. Targets spun content (auto generated), squeeze pages (all content on one main page, with popups, etc.), doorways and meta refresh (redirects user to other site), low quality guest posts

  • Penguin - penalizes low quality links (reciprocal links, paid links, links from comment spam)

  • Hummingbird - improved conversational search in the query and uses context and user location to improve results

  • Pigeon - improved local results based on user location

  • 2013 Mobile - mobile friendly version of site impacts rankings

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