How does twitter calculate its #TrendingTopics?

07 Oct How does twitter calculate its #TrendingTopics?

Twitter is awesome, or at least I think so. However, today I have seen something that looks strange with the so called TTs (Trending Topics).

Twitter defines its TTs as:

«Twitter’s Trending Topics algorithm identifies topics that are immediately popular, rather than topics that have been popular for a while or on a daily basis, to help people discover the «most breaking» news stories from across the world. We think that trending topics which capture the hottest emerging trends and topics of discussion on Twitter are the most interesting».

Just a few hours ago the news got out that Steve Jobs had passed away. This obviously was twitted, retwitted and re-retwitted. After looking at the trending topics for each country at a few minutes after 12am (nightime in Spain) I saw what I already expected: Steve and Steve related hastags dominated twitter with #iSad being a top topic in 29 out of 35 sample locations (32 countries and 3 cities: Madrid, New York, two cities where I have lived and Seattle for being an important location for the tech industry).

However, to my surprise, none of these «Steve topics» were listed in the top 9 trending topics worldwide. How can that be true if #iSad dominates all major markets which probably represent > 90% of active twitter accounts?

Some interesting other data:

• Sarah Pallin was only news in Seattle (not in NYC or in the country as a whole despite her announcement that she was not running for president) and in Sweden.
• I had never heard of Tomas Tranströmer, but he sure has made a name for himself. Congratulations to him.
• Have you ever tried reading a trending topic in Japan? Good luck, unless, you understand Japaneese symbols.
• Lynyrd Skynyrd a TT, 20 years after Free Bird? Wow!!!
• Brigitte Bardot TT in Colombia, King Kong in Germany, South Park in Seattle… which I find really curious ones but must have a logical explanation at the local level.
• Bill Gates was TT in 12 locations and Stamford in 12 locations.

By the way, the picture included in this post of top trending topics was taken at 1am, an hour later after the data was collected for this post and therefore it does not match our table. However, you can still see that Steve Jobs is nowhere to be found.

You might want to read my post A review of Twitter trends in 2010, even though I am no longer as confident in the accuracy of their formulas used to calculate these TTs.