Algorithm, Search & Distribution
Authoritative sources
Also called: authoritative content, news authority
On subjects where a wrong answer does damage, such as breaking news, health, finance and science, YouTube gives weight to sources it has assessed as authoritative instead of ranking on engagement alone. Human evaluators working to published rating guidelines make part of that assessment, judging the speaker's standing and whether the video delivers what it promised. You can see the result in dedicated news and health shelves and in what gets recommended alongside those subjects.
The common misreading is that authority means size. The assessment looks at the source's standing on the specific topic, so a large channel with no credentials in health gets no free pass.