1. Measuring User Influence in Twitter: The Million Follower Fallacy Meeyoung Cha Hamed Haddadi Fabricio Benevenuto Krishna P. Gummadi

2. INFLUENCE The power or capacity of causing an effect in indirect or intangible ways. - Merriam Webster dictionary

3. GOAL Comparing three measures of influence: indegree, retweets and mentions Investigating the dynamics of user influence over topics and time Characterize behaviors that make ordinary individuals gain high influence over a short period of time

4. MOTIVATION Understand how businesses operate and how a society functions Studying influence patterns to get knowledge of certain trends and innovations Enable advertisers and marketers to design effective campaigns.

5. Theories 1.The traditional view: Small number of influential people drive trends on behalf of majority of ordinary people 2.Modern view: Opinions of peers and friends matter more than opinion of influentials.

6. Measuring influence on Twitter Three measurements of influence: - Indegree influence: Number of followers of the user indicating size of the audience for that user - Retweet influence: Number of retweets containing one’s name indicating ability to generate content with pass-along value. - Mention influence: Number of replies to the user indicating ability of user to engage others in a conversation

7. DATASET Collected 54,981,152 in-use user accounts, which were connected to each other by 1,963,263,821 social links. Gathered the tweets generated by all the users since early days which amounts to 1,755,925,520 tweets. Focus on the largest component of the network which contains 99% of the links and tweets. After filtering, measure influence for 6,189,636 users on the entire set of users.

8. COMPARING USER INFLUENCE Ordered rank list of users for each of the three measures. Spearman’s rank correlation coefficient used as a measure of strength of association between two rank sets. A perfect positive correlation is +1 A perfect negative correlation is -1

9. COMPARING USER INFLUENCE

10. TOP USERS Followers count – Public figures and news sources Get a lot of attention from their audience Retweets – Content Aggregation Service like news channels & news sources, businessmen. Retweets are about the content and contain URLs Mentions – Celebrities, Known Figures. Ordinary users show great passion for celebrities

11. Relative Influence Ranks Indegree has a low correlation with retweets and mentions.

12. Identifying target topics Measure across 3 diverse topics : the Iranian presidential election, the outbreak of the H1N1 influenza and the death of Michael Jackson. Tweets were extracted from twitter using selected keywords.

13. Influence across topics Distribution of user ranks for retweets and mentions follows power law pattern

14. Influence across topics Measure variation of a user’s influence across the three topics using Spearman’s rank correlation coefficient Observed strong correlation between topics Most influential users hold influence across a range of topics. Top users similar for all the three topics. Highest for top 1%.

15. Retweet influence ranks

16. Influence over Time Selected top 100 users based on 3 measures Calculate probability Ρ, random tweet posted on Twitter during a 15 day period is a retweet (or a mention) of that user. Calculate this over 8 month period and normalize by the total tweets

17. Influence of ordinary users Gather top 20 users for each topic who tweet only about one topic Calculate Probability P again for these 60 users over 8 months Increase in retweets and mentions over the time period Users limited to a single topic show largest increase in influence scores

18. Conclusion Capture different perspectives of influence – indegree, retweets, mentions User’s popularity is not related to influence. Different groups of influence depending on content and name value Most influential users hold influence over variety of topics Users need to self advertise and have continuous effort and involvement to become influential over time

19. Questions 1.The authors claims that “most connected users are not necessarily the most influential” and also state that “highly popular figures hold significant influence over a variety of topics” aren’t these contradicting? 2.The topic identifies new channel based user accounts as the most popular user, but can an organisation with multiple people controlling posts, be considered as one user? 3.The paper assumes that mention is the measure of the name value of a user. However, that might not be the case every time, especially when a user is mentioned in a defaming or criticizing tweet.

20. Questions 4. What could the authors have used in place of relative influence ranks? (What other ways of ranking they could have used) 5. What are the implications of their research to businesses — both the ones wondering how to use Twitter and the ones wondering what mentions of their brands on Twitter mean? 6. With time specific data for in­degree, would it have been possible to study what topics caused an increase/decrease in followers?

21. Questions 7. Some of the author’s conclusions seem obvious. For example, influence on the Iran election increased their retweet influence during the pick of the election time while celebrities were good at getting their mentions while users who limit their tweets to single topic showed the largest influence scores. So, are they just confirming what is intuitive here? 8. How faster does a Tweeter account become influential if it is managed by multiple people, that can address several topics? (News broadcasters)