2 research outputs found
On predictability of rare events leveraging social media: a machine learning perspective
Information extracted from social media streams has been leveraged to
forecast the outcome of a large number of real-world events, from political
elections to stock market fluctuations. An increasing amount of studies
demonstrates how the analysis of social media conversations provides cheap
access to the wisdom of the crowd. However, extents and contexts in which such
forecasting power can be effectively leveraged are still unverified at least in
a systematic way. It is also unclear how social-media-based predictions compare
to those based on alternative information sources. To address these issues,
here we develop a machine learning framework that leverages social media
streams to automatically identify and predict the outcomes of soccer matches.
We focus in particular on matches in which at least one of the possible
outcomes is deemed as highly unlikely by professional bookmakers. We argue that
sport events offer a systematic approach for testing the predictive power of
social media, and allow to compare such power against the rigorous baselines
set by external sources. Despite such strict baselines, our framework yields
above 8% marginal profit when used to inform simple betting strategies. The
system is based on real-time sentiment analysis and exploits data collected
immediately before the games, allowing for informed bets. We discuss the
rationale behind our approach, describe the learning framework, its prediction
performance and the return it provides as compared to a set of betting
strategies. To test our framework we use both historical Twitter data from the
2014 FIFA World Cup games, and real-time Twitter data collected by monitoring
the conversations about all soccer matches of four major European tournaments
(FA Premier League, Serie A, La Liga, and Bundesliga), and the 2014 UEFA
Champions League, during the period between Oct. 25th 2014 and Nov. 26th 2014.Comment: 10 pages, 10 tables, 8 figure
Urban Planning / #London2012: Towards citizen-contributed urban planning through sentiment analysis of twitter data
The dynamic nature of cities, understood as complex systems with a variety of concurring factors, poses significant challenges to urban analysis for supporting planning processes. This particularly applies to large urban events because their characteristics often contradict daily planning routines. Due to the availability of large amounts of data, social media offer the possibility for fine-scale spatial and temporal analysis in this context, especially regarding public emotions related to varied topics. Thus, this article proposes a combined approach for analyzing large sports events considering event days vs comparison days (before or after the event) and different user groups (residents vs visitors), as well as integrating sentiment analysis and topic extraction. Our results based on various analyses of tweets demonstrate that different spatial and temporal patterns can be identified, clearly distinguishing both residents and visitors, along with positive or negative sentiment. Furthermore, we could assign tweets to specific urban events or extract topics related to the transportation infrastructure. Although the results are potentially able to support urban planning processes of large events, the approach still shows some limitations including well-known biases in social media or shortcomings in identifying the user groups and in the topic modeling approach.(VLID)253312