Who is most influential on Twitter? Academic formula rates tweeters

Academics at Imperial College London have launched a tool that can rank the most influential tweeters on any topic.

So far they have collected millions of tweets as part of their analysis on subjects such as David Cameron, Manchester United and the Glastonbury Festival.

Their method gives Twitter users a score, called the T-index, based on how active they are and how often their posts are retweeted.

Unlike other measures of influence produced by social media analytics companies, the T-index is specific to a particular topic of interest, and the process that calculates the score is transparent.

The T-index is expected to be useful for digital agencies, advertising companies, brands and political groups for identifying the most influential voices on social media.

The team behind the T-index launched the tool by revealing the 10 most influential tweeters on five topics.

The writer Marcus Chown (@marcuschown) was rated most influential about David Cameron and music magazine NME (@NME) ranked highest on the most recent Glastonbury Festival.

From looking at over five million tweets, the two most influential tweeters on Manchester United were  Indonesian fansites (@indomanutd and @OneLoveTo_MU), while the official Premier League Twitter account (@premierleague) was in third place.

On Burberry and the recent movie World War Z, the brands’ official accounts (@burberry and @WorldWarZMovie) had the highest T-index scores.

The formula is based on the H-index, a score used to measure the influence of academic authors based on research activity and citations in journals.

A tweeter’s T-index takes into account the number of tweets they have written about the topic and the number of retweets they have received. To get a high score, a user must be both prolific and be retweeted frequently.

In the next year, the team hope to make it possible for any user to enter their own keywords and find out the most influential tweeters on any topic.

Professor Lord Ara Darzi, Director of the Institute of Global Health Innovation at Imperial, said: “'We first became interested in measuring influence in social media during the recent  reforms in the health service, when it became clear that Twitter had become an important forum for discussions about the changes. We wanted to find some way of determining how influential different individuals were who were tweeting about the reforms and published a research article detailing our findings.

 “We then realised this metric could be more widely used across Twitter to measure key influencers in any topic from fashion brands, to public events to major geopolitical events. The results we’re getting from the topics we’ve analysed so far are fascinating, and certainly tell us more than existing metrics of influence currently in use.”

Dr Dominic King, a Clinical Lecturer in Surgery at Imperial College London, said: “There are lots of companies that measure influence on Twitter, but they usually don’t tell you how they do it. They also focus on the individual rather than a topic.”

“The T-index is a simple, transparent score that measures how influential someone is based on the quality and quantity of their output on a specific subject. The method is open to everyone, so people can discuss how useful it is as a metric.

“The results show that bloggers and independent voices can have their messages disseminated to a wider audience than established news providers. For tweets about David Cameron, Marcus Chown and Chunky Mark have higher T-indexes than established media providers like the Guardian and Daily Mirror.

“We also provide information on the most popular tweets overall about each topic. These are almost always from celebrities such as Stephen Fry, Lady Gaga or members of One Direction. But while one tweet about a topic may stimulate a peak of interest, it’s likely to be short-term. The T-index measures sustained influence.”

The full results can be found at www.t-index.com

An explanation of how the T index is calculated is available at http://www.tindex.co.uk/how-t-index-works

See the press release of this article