The time between a user clicking a search result and returning to the SERP. A long dwell time suggests the result satisfied the query; a short dwell time before a return-and-reclick suggests it didn't (see also: pogo-sticking). Dwell time is not directly observable to Google for most sessions and Google representatives have repeatedly stated it is not used as a direct ranking signal. The concept persists in SEO discussion because it correlates with ranking — well-ranking pages tend to have long dwell times — but the causation is the other way round: relevant pages get long dwell times because they're good.