1. Flickr the framework of Flickr

2. Observe them  How many photos does each user offer?  How many tags does each photo have?  The tag hot-list  How many comments does each photo have?  The ratio of the geo-tagged photos.

3. dataset  European Travel on Flickr http://www.flickr.com/groups/europe05/  1154 members  500- providers  About 15000(pretended) photos  Actual 4500 photos

4. How many photos does each user offer?

6.  1 photo : 77 users  2 photos : 85 users  3 photos : 44 users  4 photos : 56 users  5 photos : 29 users  6 photos : 24 users  7 photos : 21 users

7. How many photos does each user offer?  Top 10 providers has 20% photos.  Top 20 providers has 30% photos.  Top 53 providers has 50% photos.  486 providers / 1154 members

8. How many photos does each user offer?  Visit the top 10 providers ’ albums.  See their photos, photosets and groups

9. Top1 (195 photos, England)  http://www.flickr.com/photos/771850 53@N00 http://www.flickr.com/photos/771850 53@N00  Photoset: UK, Paris, Crete, Switzerland, USA Group: France image, This is Europe, Top20 France, TRAVEL Photography

10. How many photos does each user offer?  Not easy to build a dataset by tracing group members ’ albums automatically (by Flickr API) because many of the photos are beside.  Some people only upload the photos to associated group and not in their own album.

11. How many photos does each user offer?  But we can still expand our dataset from some members ’ photos approximately. (manually)  Through the groups the members belong to, we can find other suitable groups.

12. How many tags does each photo have?

14.  209 (5%) photos without any tag  1tag : 135 photos  2tags : 302 photos  3tags : 270 photos  4tags : 319 photos  5tags : 302 photos  6tags : 392 photos  7tags : 345 photos  8tags : 262 photos  9tags : 265 photos

15. How many tags does each photo have?  62131 photos  5069 (8%) without any tag

16. How many tags does each photo have?  Most of the photos have non-zero tags.  Not really a power-law distribution, photos < 10 tags are common and few has more than 10 tags.

17. The tag hot-list  European travel 446 Europe + 427 europe + 121 europa + 105 Europa = 1009 549 (1st) travel + 135 Travel = 684

18. The tag hot-list  Country : 334 France + 264 france = 598 275 Italy + 242 italy + 119 italia = 636 202 spain + 187 Spain = 389

19. The tag hot-list  Scene  138 landscape  166 architecture  125 water  114 church  110 sky  101 sea  97 building  87 river

20. Why we tag?

21. Why we tag? Self/Organization: Search and Retrieval  traditional annotation motivations in personal photo collections  tag specifically to later retrieve their pictures for sharing  tag for personal organization purposes

22. Why we tag? Self/Communication: Memory and Context  aid future recall of the situation it depicts  adding context is the traditional motivation for annotating printed photographs  the memory function of tags was still not a popular motivation.

23. Why we tag? Social/Organization: Public Search and Photo Pools  Making their photos findable by others  Enrich and share experiences  Be discovered by anyone who may be interested in the photo

24. Why we tag? Social/Communication: Context and Signaling  communicate contextual information to others about the image  added these contextual tags for the benefit of known others, such as friends or family  For privacy, friends or family would understand what the tags meant

25. Why we tag? Summary for motivations  tags can play several roles

26. Why we tag? conclusion  organization for oneself is a more common motivation than communication for oneself  over half of our participants used tags for personal search and retrieval; very few were motivated to tag for personal memory

27. Why we tag? Conclusion (cont.)  communication with friends and family is a more common motivation than organization for friends and family  organization for the general public is a much more common motivation than communication.

28. How many comments does each photo have?

30.  1711 (38%) photos have no comments  Unlike tags, it ’ s a power-law distribution

31. The ratio of the geo-tagged photos  Photo counts = 4497  With geo counts = 1182 (26%)  Without geo counts = 3315

32. Future work  Work with Winston's "Video Search Reranking" to think about how to design a query

33. Reference  Why We Tag: Motivations for Annotation in Mobile and Online Media (2007 ACM)  http://www.flickr.com/services/api/