Google uses the concept in its search quality rater guidelines and in its documentation “Creating helpful, reliable, people-first content”. It states that trust is the most important of the four aspects.
According to Google, E-E-A-T itself is not a specific ranking factor. Instead, Google's systems combine various signals meant to identify content with strong E-E-A-T. Quality raters assess search results but do not directly influence rankings.
In practice, this means naming authors and their expertise, citing sources, showing first-hand experience and presenting the company transparently. In our assessment these signals also help in AI search, because content with evidence is more likely to be used there. The GEO study supports this for citations and statistics.
An example: a tax guide written by a named tax adviser who cites the relevant legislation shows expertise and trustworthiness far more clearly than an anonymous text without sources.