Engagement – Google is increasingly weighting engagement and user experience metrics more heavily. You can impact this by making sure your content answers the questions searchers are asking so that they’re likely to stay on your page and engage with your content. Make sure your pages load quickly and don’t have design elements (such as overly aggressive ads above the content) that would be likely to turn searchers off and send them away.
Another example when the “nofollow" attribute can come handy are widget links. If you are using a third party's widget to enrich the experience of your site and engage users, check if it contains any links that you did not intend to place on your site along with the widget. Some widgets may add links to your site which are not your editorial choice and contain anchor text that you as a webmaster may not control. If removing such unwanted links from the widget is not possible, you can always disable them with “nofollow" attribute. If you create a widget for functionality or content that you provide, make sure to include the nofollow on links in the default code snippet.
However, we do expect websites of large companies and organizations to put a great deal of effort into creating a good user experience on their website, including having helpful SC. For large websites, SC may be one of the primary ways that users explore the website and find MC, and a lack of helpful SC on large websites with a lot of content may be a reason for a Low rating.
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.