How the Live Web Feels about Events
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Transcript of How the Live Web Feels about Events
George Valkanas Dimitrios Gunopulos
How the Live Web Feels about Events
Dept. of Informatics & TelecommunicationsUniversity of Athens, Greece
22nd ACM CIKM ConferenceBurlingame, CA, USA
October 29th, 2013
The Web evolves...
tEarly days…
Now
Forums
Online Services
WEB
USERSWho is he?
static dynamic
…and research questions emerge!
• Making sense of the content– Predictions– User profiling / Behaviorism– Event Detection
• Recommendations• Community Detection
Why Event Detection?
• Real-time news reporting – Middle East turmoil
• Emergency response / Disaster Management– Japanese Earthquakes– 2007 Southern California Wildfires
• Decision Making– Political Debates
– Stock Market
• Resource allocation
Formalizing an Event
• What is an event?An event e is a real-world phenomenon, that
occurred at some time t and is usually tied to a
location l*
• In addition to time and place, we want some textual description, to understand it
• Soft Constraint: Identify events as theyoccur, or as promptly as possible
*Y. Yang et al, "Learning approaches for Detecting and Tracking news events", IEEE Intelligent Systems Special Issue 1999
Event Detection, not so easy!
Voluminous Data*
– 200M active users– 400M tweets / day
Continuous input stream
Highly noisy
Personal writing style
Very short text
*Twitter Stats: https://business.twitter.com/audiences-twitter
Existing Techniques
• Trend detection– Prone to large
audiences, e.g. fan base
• Online clustering– Computationally
Expensive– Short messages
• Topic monitoring– Assumes event is known
Cognitive & Affective Theories of Emotions
• Events affect users
Cognitive & Affective Theories of Emotions
• Events affect users• Users feel compelled to externalize their
thoughts, as a result of such external stimuli
#@$*!!!
Thoughts convey emotion
Workflow Overview
Objective: Identify groups of users with sudden changes in aggregate emotional state
– Resembles outlier detection
Geographical Group Monitoring
• Geographical Groups– Covers the need for the event’s location l– Inherently dealing with large groups
Emotion Classification
7 Emotions*
– Anger– Fear– Disgust– Happiness– Sadness– Surprise
– None
* P. Ekman et al, “Emotion in the human face: guide-lines for research and an integration of findings”, Pergamon Press, 1972
Approximating Emotional Distributions (1)
at
U2
U1
U3 U1
U4
U2
U1
U1
U2
U3
U4
U3
U4
U3
U4
3a t3 7 2
• Approximate PDF w/ Kernels– Online technique – fast updating
Approximating Emotional Distributions (2)
at
U2
U1
U3 U1
U4
U2
U1
U1
U2
U3
U4
U3
U4
U3
U4
3a t3 7 2
• Approximate PDF w/ Kernels– Online technique – fast updating– Allows for Sampling– Basis for outlier detection
Event Extraction and Presentation
Experimental Setup
• Twitter data– Gardenhose access (10% public tweets)– April – May 2012 ( ~300M tweets )
• Keep users:– From: Canada, France, Greece, Germany, Ireland, Spain, UK, US– Speaking: English, Spanish, German, Greek– ~33.5M tweets, ~400K unique users
• Replay the stream, ordered by timestamp– No other pre-cleaning
• Technical specs– Java 1.6– Quad Core @3.5, 16Gb RAM– 3 runs average
Preliminary Experiments
• Efficiency (in ms)
• Classification Accuracy– Annotated Gold Standard (~7K tweets)
• (available)
– Majority class: 34%– C4.5: 64,39% 10-fold
Temporality of Emotions
1 minute aggregations
Message 1: Sampling plays its role!Message 2: Fast-paced medium, w/ mid-sized temporal momentum
Locality of Emotions5 minute aggregations
Global Aggregation
Message: Grouping by location makes sense!
Effectiveness in Event Detection
Effectiveness in Event Detection
• Sports
Effectiveness in Event Detection
• Sports• Politics
Effectiveness in Event Detection
• Sports• Politics
• Earthquake
Effectiveness in Event Detection
• Sports• Politics
• Earthquake• Celebrity
Effectiveness in Event Detection
• Sports• Politics
• Earthquake• Celebrity
• Music Contest
Conclusions
• Affective-based event detection in the Live Web
• Affective tweets exhibit temporal & spatial locality
• Our technique can detect various event types
• Annotated gold standard, which we make available to the community
Thank you!
Questions?