The terms SEO experts often start with are page authority (PA) and domain authority (DA). DA, a concept in fact coined by Moz, is a 100-point scale that predicts how well a website will rank on search engines. PA is the modern umbrella term for what started as Google's original PageRank algorithm, developed by co-founders Larry Page and Sergey Brin. Google still uses PageRank internally but has gradually stopped supporting the increasingly irrelevant metric, which it now rarely updates. PA is the custom metric each SEO vendor now calculates independently to gauge and rate (again, on a scale of 100) the link structure and authoritative strength of an individual page on any given domain. There is an SEO industry debate as to the validity of PA and DA, and how much influence the PageRank algorithm still holds in Google results (more on that in a bit), but outside of Google's own analytics, they're the most widely accepted metrics out there.
Being ‘relevant’ comes down to keywords & key phrases – in domain names, URLs, Title Elements, the number of times they are repeated in text on the page, text in image alt tags, rich markup and importantly in keyword links to the page in question. If you are relying on manipulating hidden elements on a page to do well in Google, you’ll probably trigger spam filters. If it is ‘hidden’ in on-page elements – beware relying on it too much to improve your rankings.
Difficulty scores are the SEO market's answer to the patchwork state of all the data out there. All five tools we tested stood out because they do offer some version of a difficulty metric, or one holistic 1-100 score of how difficult it would be for your page to rank organically (without paying Google) on a particular keyword. Difficulty scores are inherently subjective, and each tool calculates it uniquely. In general, it incorporates PA, DA, and other factors, including search volume on the keyword, how heavily paid search ads are influencing the results, and how the strong the competition is in each spot on the current search results page.
Hi Noya, all the info suggests that dwell time IS taken into account in search ranking, and we know that Google measures time on page and bounce rate in Analytics, too. Plus the search engine gets smarter all the time. With the machine learning component of RankBrain, we wouldn’t be surprised if Google can tell the difference between sites where visitors stick around, bounces where the visitor gets an answer immediately, and bounces where the visitor keeps searching.