San Francisco, March 4 : Micro-blogging site Twitter has reportedly announced an expansion to its Birdwatch scheme, which sees volunteer fact-checkers vet potentially-misleading tweets. The company said that, as of right now, a small randomised group of US-based users will see fact-checking notes appended to controversial missives, reports Engadget. Rather than a full rollout, however, Twitter said that this is more an expansion in the "visibility of the pilot". It intends to help gain more feedback from a broader number of users rather than anything more wide-ranging. Birdwatch works by allowing these unpaid fact-checkers to attach contextual notes which, until now, have only been visible on a separate Birdwatch site. These notes won't, however, reach general users during this expanded trial unless enough other Birdwatch volunteers vote on them positively. And these votes will need to come from users with a broad number of "different perspectives," which Twitter defines as having voted in opposition to their fellow volunteers. The move comes just 48 hours after The Washington Post posted a report criticising Twitter for failing to get Birdwatch rolled out to its global user base. Birdwatch is described as being "invisible to ordinary Twitter users," and cited figures saying that, before Russia's invasion of Ukraine, less than 50 tweets per day were being flagged and appended by volunteers. /IANS