Googlesrankingfactors2011 120314055657-phpapp01


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Googlesrankingfactors2011 120314055657-phpapp01

  1. 1. Google’s Ranking Factors 2011 Rand Fishkin, SEOmoz CEO, April 2011 Early data from SEOmoz’s survey of 132 SEO professionals and correlation data from 10,000+ keyword rankings Download at:
  2. 2. SEOmoz Makes Software! We don’t offer consulting.
  3. 3. Understanding, Interpreting & Using Survey Opinion Data Everybody’s wrong sometimes, but there’s a lot we can learn from the aggregation of opinions
  4. 4. http:/ thanks to all who contributed their time to take the survey! #1: Opinions are Not Fact (these are smart people, but they can’t know everything about Google’s rankings) #2: Not Everyone Agrees (standard deviation can help show us the degree of consensus) #3: Data is Still Preliminary (these are raw responses without any filtering)
  5. 5. Understanding, Interpreting & Using Correlation Data This is powerful, useful information, but with that power comes responsibility to present it accurately
  6. 6. http:/ details, including complete documentation and the raw dataset will be released in May with the published version of the 2011 Ranking Factors Methodology 10,271 Keywords, pulled from Google AdWords US Suggestions (all SERPs were pulled from Google in March 2011, after the Panda/Farmer update) Top 30 Results Retrieved for Each Keyword (excluding all vertical/non-standard results) Correlations are for Pages/Sites that Appear Higher in the Top 30 (we use the mean of Spearman’s correlation coefficient across all SERPs) Results Where <2 URLs Contain a Given Feature Are Excluded (this also holds true for results where all the URLs contain the same values for a feature)
  7. 7. http:/ Dolphins who swim at the front of the pod tend to have larger dorsal fins, more muscular tails and more damage on their flippers. The first two might have a causal link, but the damaged flippers is likely a result of swimming at the front (i.e. having damaged flippers doesn’t make a dolphin a better front-of-the-pod-swimmer). Likewise, with ranking correlations, there’s probably many features that are correlated but not necessarily the cause of the positive/negative rankings. Correlation & Dolphins
  8. 8. http:/ because a feature is correlated, even very highly, doesn’t necessarily mean that improving that metric on your site will necessarily improve your rankings. Correlation IS NOT Causation But, will adding more characters to the HTML code of a page increase rankings? Probably not. Earning more linking root domains to a URL may indeed increase that page’s ranking.
  9. 9. http:/ error won’t be reported in this presentation, but it’s less than 0.0035 for all of Spearman correlation results (so we can feel quite confident about our numbers) How Confident Can We Be in the Accuracy of these Correlations? Because we have such a large data set, standard error is extremely low. This means even for small correlations, our estimates of the mean correlation are close to the actual mean correlation across all searches.
  10. 10. http:/ rough rule of thumb with linear fit numbers is that they explain the number squared of the system’s variance. Thus, a factor with correlation 0.3 would explain ~9% of Google’s algorithm. Do Correlations in this Range Have Value/Meaning? A factor w/ 1.0 correlation would explain 100% of Google’s algorithm across 10K+ keywords Most of our data is in this range
  11. 11. Are You Ready for Some Data?!
  12. 12. Overall Algorithmic Factors These compare opinion/survey data from 2009 vs. 2011
  13. 13. http:/ 2009, link-based factors (page and domain-level) comprised 65%+ of voters’ algorithmic assessment
  14. 14. http:/ In 2011, link-based factors (page and domain-level) have shrunk in the voters’ minds to only ~45% of algorithmic components. Note: because the question options changed slightly (and more options were added), direct comparison may not be entirely fair.
  15. 15. Page-Specific Link Signals These metrics are based on links that point specifically to the ranking page
  16. 16. http:/ opinion data, voters ordered the factors from most important to least. Thus, when looking at opinion stats, the factor voters felt was most important will have the smallest rank. Most Important Page-Level Link Factors (as voted on by 132 SEOs) My guess: Some voters didn’t fully understand the “linking c-blocks” choice
  17. 17. http:/ data is exactly what an SEO would expect – the more diverse the sources, the greater the correlation with higher rankings. These numbers are relatively similar to June 2010 data. In the rest of this deck, we’ll use linking c-blocks as a reference point, hence the red 
  18. 18. http:/ anchor text matches have greater correlation than exact match. This might be correlation only, or could indicate that the common SEO wisdom to vary anchor text is accurate. Correlations of Page-Level, Anchor Text-Based Link Data No Surprise: Total links (including internal) w/ anchor text is less well-correlated than external links w/ anchor text
  19. 19. http:/ are my personal takeaways from the data; others’ interpretations may vary Rand’s Takeaways #1: SEOs Believe the Power of Links Has Declined (correlation of link data w/ rankings has fallen slightly from 2010 to 2011 as well) #2: Diversity of Links > Raw Quantity (This fits well with most SEOs expectations. Also helps me feel better about the correlation data) #3: Exact Match Anchor Text Appears Slightly Less Well Correlated than Partial Anchor Text in External Links (This was surprising to me, though from Google’s perspective, it makes good sense. The aggregated voter opinions agreed with this, too.)
  20. 20. Domain-Wide Link Signals These metrics are based on links that point to anywhere on the ranking domain
  21. 21. http:/ seem to believe that diversity/quantity is more important that quality. Most Important Domain-Level Link Factors (as voted on by 132 SEOs) C-Blocks: Likely the same vote interpretation issue as with page-level
  22. 22. http:/ link data is surprisingly similar to page-level link data in correlation Correlation of Domain-Level Link Data Nice Work! Excluding the “c-blocks” issue, voters + correlations match nicely.
  23. 23. http:/ Rand’s Takeaways #1: Google May Rank Pages, But Domains Matter Too (the closeness of correlation data and the opinions of voters both back this up) #2: Link Velocity & Diversity of Link Types Would Be Interesting to Measure Given Voters’ Opinions (Hopefully we can look at these in future analyses) #3: Correlations w/ “All” Links vs. Followed-Only is Odd (Let’s take a closer link at these correlations)
  24. 24. Something Funny About Nofollows These compare followed vs. nofollowed links to the domain + page
  25. 25. http:/ numbers exhibit why we like to build ranking models using machine learning. Models can help determine whether nofollowed links have a causal impact or whether it’s mere correlation. Correlation of Followed vs. Nofollowed Links Nofollowed Matters? Many SEOs have been saying that nofollow links can help w/ rankings. The correlation suggests maybe they’re right.
  26. 26. http:/ to know for sure, but based on this data, it could go either way – nofollowed links, in some way, seem to have a positive impact on rankings. Some live tests are likely in order  Correlation of Followed Links to Nofollowed Links (i.e. Are nofollowed links well correlated w/ rankings only because they’re indicative of followed links?)
  27. 27. On-Page Signals These metrics are based on keyword usage and features of the ranking document
  28. 28. http:/ We surveyed SEOs about more on-page optimization features, but I didn’t include them all on this chart as it would make the labels very tiny and hard to read  Most Important On-Page, Keyword-Use Factors (as voted on by 132 SEOs) My guess: Some voters didn’t fully understand the internal/external link anchors choice
  29. 29. http:/ is just a sampling of the on-page elements we observed; some factors haven’t yet been calculated and thus couldn’t be compared for this presentation. They’ll be in the full version. Curious: Longer documents seem to rank better than shorter ones Keyword-based factors are generally less well correlated w/ higher rankings than links. Correlation of On-Page Keyword-Use Elements
  30. 30. http:/’s a longtime rumor that linking externally to (or Microsoft on Bing) helps with rankings. It’s comforting to see that correlation-wise, linking to MS is better on Google  Correlation of On-Page Keyword-Use Elements The theory that AdSense use boosts rankings isn’t supported by the data More reason to believe Google when they say page load speed is a factor, but a very small one
  31. 31. http:/ definitely need to look at more on-page factors in the data for the full report, too. Rand’s Takeaways #1: Very Tough to Differentiate w/ On-Page Optimization (as in the past, the data suggests that lots of results are getting on-page right) #2: Longer/Larger Documents Tend to Rank Better (It could be that post-Panda/Farmer update, robust content is rewarded more) #3: Long Titles + URLs are Still Likely Bad for SEO (In addition to the negative correlations, they’re harder to share, to type-in and to link to) #4: Using Keywords Earlier in Tags/Docs Seems Wise (Correlation backs up the common wisdom that keywords closer to the top matter more)
  32. 32. Domain Name Match Signals These signals are based on data from users of Twitter, Facebook & Google Buzz via their APIs
  33. 33. Domain Name Extensions in the Search Results: Google may not love .info and .biz, but they like them better than Canadians! 
  34. 34. http:/ sample data sets are fairly comparable in every way – both come via Google AdWords suggestions, both include approx. 10K keyword rankings and both were gathered from Google US. Spearman’s Correlation with Google Rankings for Exact Match Domain Names June 2010 vs. March 2011 Whoa! The influence of exact match domain names seems to have waned considerably. Links… not so much.
  35. 35. http:/ names are still powerful (0.22 correlation for .com exacts), but perhaps losing ground. Rand’s Takeaways #1: Exact Match Domains May Not Be as Powerful (though it’s possible that both number reflect correlation-only, not causation) #2: Exact .coms Fell Farther than Any Other Factor (Possibly a lot of gaming or manipulation happening w/ those sites?) #3: Link Count Correlations Remain Similar (This fits w/ my experience and makes me more comfortable comparing the data sets)
  36. 36. Social Signals These signals are based on data from users of Twitter, Facebook & Google Buzz via their APIs
  37. 37. http:/ we didn’t ask voters for a cutoff on what they believe matters vs. doesn’t, I suspect many/most would have said that Google Buzz and Digg/Reddit/SU aren’t used in the rankings. Most Important Social Media-Based Factors (as voted on by 132 SEOs) Curious: For Twitter, voters felt authority matters more, while for Facebook, it’s raw quantity (could be because GG doesn’t have as much access to FB graph data).
  38. 38. http:/ voters thought Twitter data / tweets to URLs were more influential, Facebook’s metrics are substantially better correlated with rankings. Time to get more FB Shares! Correlation of Social Media-Based Factors (data via Topsy API & Google Buzz API) Amazing: Facebook Shares is our single highest correlated metric with higher Google rankings.
  39. 39. http:/ most link factors, 99%+ of results had data from Linkscape; for social data, this was much lower, but still high enough that standard error is below 0.0025 for each of the metrics. Percent of Results (from our 10,200 Keyword Set) in Which the Feature Was Present It amazed me that Facebook Share data was present for 61% of pages in the top 30 results
  40. 40. http:/’s correlation wanes dramatically, but Facebook features, while lower, still appear quite influential. Facebook likely deserves much more SEO attention than it currently receives. Correlation of Social Metrics, Controlling for Links (i.e. Are pages ranking well because of links and social metrics are simply good predictors of linking activity?) Raw Correlations Correlations Controlling for Links
  41. 41. http:/ more experimentation and, sadly, some gaming attempts w/ Twitter + Facebook by SEOs (and spammers) in the future. Rand’s Takeaways #1: Social is Shockingly Well-Correlated (it’s hard to doubt causation, particularly after reading the SearchEngineLand interview here) #2: Facebook may be more influential than Twitter (Or it may be that Facebook data is simply more robust/available for URLs in the SERPs) #3: Google Buzz is Probably Not in Use Directly (Since so many users simply have their Tweet streams go to Buzz, and correlation is lower) #4: We Need to Learn More About How Social is Used (Understanding how Google uses social metrics, parses “anchor text,” etc. looms large)
  42. 42. Highest Positively + Negatively Correlated Metrics Overall These are the features most indicative of higher vs. lower rankings
  43. 43. http:/ match domain is actually not in the top 8, but I thought I should include it, as it was, previously, one of the metrics most predictive of positive rankings. Top 8 Strongest Correlated Metrics
  44. 44. http:/ domain names, titles, URLs and domain names all had negative correlations with rankings. Again, I’ve included # of words in title, which isn’t technically in the top 8, but still interesting Top 8 Most Negatively Correlated Metrics Be concise and to-the-point; it’s good for users and for your rankings 
  45. 45. http:/ note that % of followed links on a page has a slightly negative correlation with rankings. Perhaps sites that make all their links out followed aren’t being careful about what they link to? Top 8 Most Negatively Correlated Metrics One of the most surprising finds in our dataset. We double-checked to be sure. 40% of URLs in the set had only followed links, and these tended to have lower Page Authority (and lower rankings) than those w/ both followed and nofollowed links. Our data scientist thinks there’s some correlation between having nofollowed and other good/natural link signals.
  46. 46. Which Domains Appeared Most Frequently in Our 10K+ SERPs?
  47. 47. http:/ Top 20 Root Domains Most Prevalent in our 10,200 keyword set (top 30 rank positions) SEOs may be disappointed to see performing so well, but classic content aggregators like + Wikipedia still beat them.
  48. 48. What do the Experts think the Future Holds?
  49. 49. http:/ there was some significant contention about issues like paid links and ads vs. content, the voters nearly all agreed that social signals and perceived user value signals have bright futures. What Do SEOs Believe Will Happen w/ Google’s Use of Ranking Features in the Future?
  50. 50. http:/ are looking forward to sharing the full data in the new version of the Search Ranking Factors report coming in ay 2011. Lots more cool info along with the full dataset will be available then. IMPORTANT! Don’t Misuse or Misattribute Correlation Data! Think of correlation data as a way of seeing features of sites that rank well, rather than a way of seeing what metrics search engines are actually measuring and counting. A well-correlated metric can often be its own reward, even if it doesn’t directly impact search engine rankings. Virtually all the data in this report reflect the best practices of inbound marketing overall – and using the data to help support these is an excellent application  Thanks much! Rand
  51. 51. Q+A Rand Fishkin, CEO & Co-Founder, SEOmoz • Twitter: @randfish • Blog: • Email: You can now try SEOmoz PRO Free! Download at: