It seems grouping and counting, then ranking the topics returned by Daily and Weekly trend API does not give the correct top topics shown in home page of twitter.com. Can anyone tell me how the "Popular topics today" and "Popular topics this week" works in http://twitter.com/? i.e. after parsing http://search.twitter.com/trends/daily.json, topics are simply counted and ranked. however, the result is about less than 50% accurate to what is displayed in the home page. Anyone knows the actual algorithm used in the site?
I just noticed yesterday that Today and Weekly list no longer have hashtag topics? Am I correct on this observation? Thanks for any lead on this.