We can infer how Google’s algorithm works based on patents the company has filed and on experiments people have run. In this 20 slides in 20 seconds apiece PechaKucha format, I review some of the history of search engines, black hat SEO, and some of the better analyses and studies out there.
The full write-up is here:
Here are the studies I reference.
Ahrefs Study: https://ahrefs.com/blog/on-page-seo/
Moz click through rate: https://moz.com/rand/queries-clicks-influence-googles-results/
Brian Dean http://backlinko.com/search-engine-ranking
Groupon experiment http://searchengineland.com/60-direct-traffic-actually-seo-195415