Many creators are familiar with the concept of E-A-T, which is used in how we evaluate if our
search ranking systems are providing helpful, relevant information. Would ordinary people feel
the results they get demonstrate E-A-T, that is: expertise, authoritativeness, and
trustworthiness? Now to better assess our results, E-A-T is gaining an E: experience.
Source: Google Webmaster Central Blog
Link: Our latest update to the quality rater guidelines: E-A-T gets an extra E for Experience