Google has updated both the Google Discover help documentation and the Google helpful content system page documentation to clarify that Google Discover uses many of the same signals as Google Search for ranking. The big news is that previously Google told us the helpful content update did not impact Discover, but now Google says it does (and then said it does not and now says it does, see updates below).
Just to be clear, we already knew that core updates and other Google ranking systems impact Google Discover. Google told us core updates could impact Google Discover performance not just once but at least twice before. But the helpful content update impacting Discover, I think, is new.
Google wrote on the revised Google Discover documentation:
"As part of Google Search, Discover makes use of many of the same signals and systems used by Search to determine what is helpful, people-first content. Given this, those looking for success with Discover should review our advice on creating helpful, reliable, people-first content."
The older version said:
"Our automated systems surface content in Discover from sites that have many individual pages that demonstrate expertise, authoritativeness, and trustworthiness (E-A-T). Those looking to improve E-A-T can consider some of the same questions we encourage site owners to consider for Search. While Search and Discover are different, the overall principles for E-A-T as it applies to content within them are similar."
Google also updated the helpful content system documentation to read:
"The system generates a site-wide signal that we consider among many other signals for use in Google Search (which includes Discover). The system automatically identifies content that seems to have little value, low-added value or is otherwise not particularly helpful to people."
The older version said:
"The system generates a site-wide signal that we consider among many other signals for ranking web pages. Our systems automatically identify content that seems to have little value, low-added value or is otherwise not particularly helpful to those doing searches."
You can see here that Google added "which includes Discover."
I don't think we had confirmation that the helpful content update / system impacted Google Discover until now, in fact, previous communication said the helpful content update did not impact Discover, that it only impacted Search.
I asked Danny Sullivan when this changed, when did the helpful content update start to impact Google Discover - I will let you know if I hear back.
Update: Danny Sullivan is looking in to when this changed, he posted here, "This is way back at launch? If so, probably correct at launch but likely changed soon after. Will check on roughly when, but it's not a new change now. It's been using the system for some time, as I understand."
Forum discussion at Mastodon.
Update 2: Danny now writes, "OK -- Discover doesn't yet use it. But the signal is available for use for anything in Google Search (including Discover), which is what the help page says. We aren't likely to confirm when/if it actually used just as we won't for each search signal. But generally, if you want to be successful with Discover, which is part of Search, it makes sense to pay attention to the things that are helpful with Search."
Update 3: Now, on March 7th, Danny said he was wrong and Google does indeed use the helpful content update for Google Discover. He posted a clarification on Mastodon saying, "Sorry for the confusion over this. Did more checking. We do indeed use it and have done so since last October. But it's a very light use. So we're leaving the page as is, but as I also said, we won't be confirming each search signal used by Discover. "If you want to be successful with Discover, which is part of Search, it makes sense to pay attention to the things that are helpful with Search."