Using Social Media to Identify Events, ACM MM 2011 | Nov 28 - Dec 1 | Scottsdale, Arizona, USA. International ACM Workshop on Social Media (WSM11).

1. Using Social Media to
Identify Events
Xueliang Liu <xueliang.liu@eurecom.fr>
Raphaël Troncy <raphael.troncy@eurecom.fr>
Benoit Huet <benoit.huet@eurecom.fr>
Multimedia Department, EURECOM, France.

2. What are Events?
Events are observable occurrence grouping
People Place Time
Experiences documented by Media
A natural way to organize media
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3. There’s a lot of information out there…
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4. Events Mining from Social Media?
Events ?
Photos from Flickr.com
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5. Related Work
 EventBurn.com
 Creating summaries about known events (searching Twitter,
Facebook, and Flickr)
 Firan et al. (CIKM’10)
 Organizing personal photos based on Social Events
 Gao et al. (WWW’11)
 Employing real-time micro-blog data to discover events
 Liu et al. (ICMR’11)
 Finding media illustrating events
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6. Observation
 Media are captured during events and shared
 Capture Time, Geo-localization
 User Tags (Annotations)
 Machine-Tag (lastfm:event=1337426)
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7. Our Event DataSet
 9 attractive venues from the EventMedia dataset
(110000 events)
Venue Name NbEvents NbPhotos NbUsers rank
Melkweg 352 6912 266 1
Koko 151 3546 155 5
HMV Forum 106 2650 130 8
111 Minna Gallery 24 1369 105 14
HMV Hammersmith Apollo 79 2124 96 20
Circolo degli Artisti 148 2571 86 29
Circolo Magnolia 79 2190 76 40
Ancienne Belgique 212 7831 56 83
Rotown 204 3623 49 101
Total : 1355 32816 -
 Event Ground Truth obtained from the official agendas
 available from individual venue websites.
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8. Detecting and Identifying Events
 Our solution consists of 3 steps:
 Location Monitoring: finding the bounding-box of venues.
 Temporal Analysis: detecting events by analyzing the
uploading behavior along time.
 Event Topic Identification: identifying detected events’ topics
through tag analysis.
14
12
10
8
6
4
2
0
10/05/01 10/05/06 10/05/11 10/05/16 10/05/21 10/05/26 10/05/31
Location Temporal Event Topic
Results
Monitoring Analysis Identification
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9. Event Detections
 Location Monitoring
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10. Venue Bounding Box Estimation
1 : INPUT : VenueName
2 : OUTPUT : BoundingBox
3 : PhotoSet []
4 : Center GetInfo(
VenueName)
5 : EventSet GetPastEvents(VenueName)
6 : foreach event in EventSet do
7: photos GetFlickrPhoto(event)
8: PhotoSet.append ( photos)
9 : end
10 : GeoSet GetGeoInfo( PhotoSet)
11 : Filter (GeoSet, Center, threshold 1km)
12 : RETURN MinRect(GeoSet)
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11. Venue Bounding Boxes (a selection)
Paradiso HMV Hammersmith Apollo
Melkweg KoKo
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12. Our Media DataSet
 Flickr Photos
 Taken in May 2010
 In either one of the 9 selected locations:
Number of Photos
Name Overlap Total
Geo-tagged Venue Name tagged
Koko 372 2040 3 2409
Rotown 90 273 1 362
Melkweg 363 700 8 1055
HMV Forum 184 412 0 596
111 Minna Gallery 937 3 0 940
Ancienne Belgique 2206 288 2 2492
Circolo degli Artisti 70 553 1 622
Circolo Magnolia 95 236 0 331
Hammersmith Apollo 287 84 0 371
Total : 4604 4589 15 9178
 Photos rarely have both geo-tag and venue name tag!
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13. Analyzing Photo Capture Dates (Flickr)
250
200
Events ?
Number of Photos
150
100
50
0
10/05/01 10/05/06 10/05/11 10/05/16 10/05/21 10/05/26 10/05/31
Days
Number of photos taken in Melkweg in May 2010
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14. Analyzing Photos Owners (Flickr)
14
12
Events ?
10
Number of Owners
8
6
4
2
0
10/05/01 10/05/06 10/05/11 10/05/16 10/05/21 10/05/26 10/05/31
Days
Number of photo owners in Melkweg in May 2010
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15. Event Detection Approach
 Based on media upload activity
 At a given time
 At a given location
 Events can be detected by:
et arg(ti T)
i
 Where
ti N photos * N owners
T : Threshold
 Venue/Event popularity
 Adaptive thresholding
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16. Event Topics Mining
 Keep the top N most frequent tags
 Result:
melkweg anouk amsterdam jemaine 2010 european flight flightoftheconchords
conchords fotc mckenzie clement tour bret evelyn
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17. Event Detection Example
111 Minna Gallery in May 2010
Number of photos * Number of photo owners
Days
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18. Results
 Evaluation of Detection alternatives:
 Thresholding function: mean vs median
 Parameters: Photo vs Owners vs Photos*Owners
Source Threshold True Detection False Detection F1
mean 43 21 0.211
Photos
median 64 51 0.279
mean 56 56 0.246
Owners
median 58 62 0.251
mean 34 18 0.172
Photos*Owners
median 67 53 0.289
 Events with no or too few photos cannot be detected!
 The Ground Truth references Events! NOT PHOTOS!
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19. Event Detection and Identification Results
Our Methods
Venues GT LastFM
Detected Matched Precision Recall
Melkweg 69 15 12(4) 0.800 0.174 44
Koko 20 15 8 (8) 0.533 0.400 0
HMV Forum 14 12 9 0.750 0.643 14
111 Minna Gallery 23 15 2(2) 0.133 0.087 0
Ancienne Belgique 38 15 9(2) 0.600 0.237 28
Rotown 16 15 8 0.533 0.500 13
Circolo degli Artisti 22 15 8(1) 0.533 0.364 12
Circolo Magnolia 25 3 1 0.333 0.040 11
Hammersmith Apollo 15 15 10 0.667 0.667 14
In total 242 120 67 0.558 0.277 136
 (*) Number of correctly identified events which are not
referenced in LastFM
 13% additional events
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20. Events at Melkweg (NL) in May 2010
Detection Results Ground Truth LastFM
Venue
Date Tags Date Title LastFM Title
parkwaydrive drive Parkway Drive / Despised Icon /
melkweg 03/05/2010 parkway 03/05/2010 Winds Of Plague / The Warriors / 50 Lions 1336473 Parkway Drive
flight flightoftheconchords Flight of the
melkweg 02/05/2010 conchords 02/05/2010 Flight Of The Conchords - UITVERKOCHT 1439320 Conchords
Flight of the
melkweg 04/05/2010 flightoftheconchords 04/05/2010 Flight Of The Conchords - UITVERKOCHT 1439407 Conchords
Mayer
mayerhawtorne mayer Hawthorne &
melkweg 05/05/2010 hawthorne 05/05/2010 Mayer Hawthorne & The County 1416229 The County
melkweg 11/05/2010 bonobo 11/05/2010 Bonobo - UITVERKOCHT 1398102 Bonobo
melkweg 14/05/2010 paulweller paul 14/05/2010 Paul Weller - UITVERKOCHT 1406677 Paul Weller
Broken Social
melkweg 18/05/2010 brokensocialscene 18/05/2010 Broken Social Scene - UITVERKOCHT 1334429 Scene
Mike Stern band with special guest Richard
melkweg 19/05/2010 mikestern richardbona 19/05/2010 Bona featuring Dave Weckl & Bob Malach
melkweg 25/05/2010 beattimemelkweg 24/05/2010 Beattime - The Kika Edition
melkweg 26/05/2010 beattime 24/05/2010 Beattime - The Kika Edition
Off Centre - day 3 - night met Kode 9 / Falty
melkweg 28/05/2010 offcentre 28/05/2010 DL / Gold Panda / Kelpe
melkweg 30/05/2010 joannanewsom 30/05/2010 Joanna Newsom 1425481 Joanna Newsom
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21. Mike Stern @ Melkweg on May 19th 2010
GroundTruth
Title: Mike Stern band with special guest Richard Bona
featuring Dave Weckl & Bob Malach
Time:2010-5-19

22. Mike Stern @ Melkweg on May 19th 2010
Top Tags
Mikestern
Richardbona
19mei2010
Daveweckl
Bobmalach
Melkweg
Amsterdammelkweg
Concert
Concertphotography
concertphoto
Time
2010-5-19
GroundTruth
Title: Mike Stern band with special guest Richard Bona
featuring Dave Weckl & Bob Malach
Time:2010-5-19

23. Beattime @ Melkweg on May 24th 2010
GroundTruth
Title: Beattime - The Kika Edition
Time: 2010-5-24
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24. Beattime @ Melkweg on May 24th 2010
Top Tags
24052010
BeattimeMelkweg
amsterdam
Nederland
Netherlands
Sp550uznoord
Holland
Olympus
Cityscape
Time
2010-5-25
GroundTruth
Title: Beattime - The Kika Edition
Time: 2010-5-24

25. Conclusion
 A novel approach for automatically detecting social
events is presented
 The key idea consists in temporally monitoring media
shared on social web sites at a specific location (Geo
Localized Photo)
 Automatic Efficient Social Event Detection and
Identification can be achieved
 Meta-Objective / Future work: Social Event analysis
based on connections between events, media and
participants
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26. Thank you for your attention…
Q&A
http://www.slideshare.net/huetbenoit/wsm2011
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