You may remember the awesome chart from 2014 showing Search Engine Ranking Factors. The 2015 Chart is now out and it shows clear refinement of the factors that affect search engine rankings. Here is the link to download the chart.
But before we get all excited about implementing the recommendations in the new chart, what we have been anticipating for a long time has begun. Google has announced that 15% of search queries are now being processed using Artificial Intelligence (AI). This means that ranking factors are less defined since the AI ranks using 'thought' instead of 'defined factors.' Here is an article about this development.
According to the article, it also seems the AI is also being used in the queries that are processed by Google algorithms, and the AI now may be the third-most-important ranking signal. If true, that means the third-most-important signal is not definable or predictable.
So, while the new chart is more refined and more helpful than the previous version, it seems there is a factor (at Google at least) that cannot be predicted or influenced. That means that writing and structuring your website for users and their expected intentions is all-the-more important.