In a Google office hours hangout the question was asked if similar kinds of pages, like category pages, had aggregated core web vitals scores. John Mueller answered
A person asked if similar pages were grouped and scored together. The reason this matters is because some sections might not have enough visits by Chrome users to provide data back to Google for core web vitals scoring.
The question asked was:
“John, you don’t group URLs by type, do you? Because we’ve noticed something similar, that category pages also don’t have enough Chrome views in order to give perfect data.
But we get messages saying these are similar pages.”
John Mueller’s answer was fast and without any ambiguity.
“Yeah. We do that. We do that with the Chrome User Experience Report data, the field real-world data, essentially, where we try to recognize when there are pages that are similar enough that we could group them together.”
So what John is saying is that if Google is grouping similar pages together.
Next he follows up and talks about the scoring of those groups.
“And then that could be… I don’t know how that would look in practice.
It could be something where all of your category pages are in one group and we say, well, these pages perform similarly. So if we find a new URL that is also a part of this group, we don’t have to have data for that new URL. We can rely on the data for the group overall.”
That confirms that if Google doesn’t have core web vitals data for an individual pages that Google will simply assign it the overall score for the group that it is assigned to.
Next Mueller discusses how this might create anomalies in the Google Search Console report.
“And I think that sometimes throws things off a little bit in the sense of we might have one group, essentially, for a site. But that could contain thousands of URLs.
So, in the report in Search Console, I think we would report that as thousands of URLs have this problem.
And then we just show that one part of the group, essentially.
But not seeing any data at all in one report and seeing a lot of data in the other report, that feels kind of weird.”
Core Web Vitals Group Scoring
That Google groups URLs together for scoring is something to keep in mind.
Aggregating scores could explain why some publishers and SEOs might not see fixes acknowledged in their core web vitals report if just a section of a site is addressed for a fix but not the entire site.
The scores of the fixed sections might get aggregated with the scores of sections that are being crawled and scored.
Watch the Google Office Hours Hangout
At the 10:34 minute mark