Article Reads is a metric that counts the number of times a real person opened an article, spent at least 10 seconds on it, and actually started consuming the content.
Unlike Pageviews, which is a metric that can only measure browser events, Article Reads is a metric that takes in consideration tab-in focus and human interaction with the page (e.g. mouse clicking, scrolling, etc.)
Social Actions represent the combined number of key social actions across major social network platforms. Data is collected from the available public APIs of the networks.
Read Depth is a complex metric that reveals how deeply a visitor has got into reading a piece of content. It takes into consideration true attention time, length of the text, scroll-depth, and the average time it takes for a reader to consume the content. It analyzes only the article content on the page, disregarding all other elements.
Page Depth calculates the average number of pages visited after a reader opens the initial page, or article.
Attention Time calculates the time a user actually spends on the page reading the content. This is what we in the industry often refer to as "engaged time". It doesn't count 'idle time' - i.e. those seven minutes you left to make a cup of coffee and left the browser window open.