Perhaps the feature hasn't been highly cited enough. I don't remember having noticed it before, but I've found a few references to it on the web dating back to May, 2011.

Here's an undated article in Google News Support, which includes a comment about what the feature signifies...

Google News expandable story boxes
[support.google.com...]

Highly Cited: the article that appears to be most frequently. referenced by other articles in this story.

The Google News Support article also notes a few features apparently related to sentiment analysis (opinion, satire, in-depth), and those do ring a bell, making me believe we'd discussed that here*. I'm not sure whether "opinion", eg, is so identified because Google's analyzed it by content, or simply because it's labeled as opinion within the news publication.

* Google "News" is a hard topic to search for in this forum because of the name of the forum.

the article that appears to be most frequently. referenced by other articles in this story.

It sounds like that label should actually be "Most Cited" rather than simply "Highly Cited", doesn't it?

"Most Cited" rather than simply "Highly Cited"

Just playing devils advocate... maybe they feel that "most cited" is too broad a claim, since they also say "appears to be most frequently referenced", and their sample size isn't necessarily all encompassing.

Been there for at least 2 years in searches, I make , which are scientifically based.

I've certainly not seen it before.

I was trying to assess the badge to see if it was the story most cited. It's quite hard to tell, but i'll now start watching for it more closely.