A%20Multi-player%20Online%20Game%20for%20Semantic%20Annotation

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A Multi-player Online Game for Semantic Annotation
PhotoSlap

• Hernisa Kacorri

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what
http//photoslap.csie.org
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why

• Photo Metadata
• People Who are in the picture?
• Objects What objects are in the picture?
• Event What was the event?

• Time When was the photo taken?
• Location Where was the picture taken?

• manually annotating
• Tedious and time-consuming
• Need for incentives
• monetary rewards
• promoting a common good
• fun

• automatic annotation
• Embedded metadata in standard JPEG format (EXIF)
• time
• resolution
• ISO
• aperture
• shutter speed
• GPS-equipped devices
• location

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related work

• Human Computation
• examples
• Label Me web-based image annotation tool
• Riya visual search engine (combines manual
  labeling machine learning)
• ESP Game interactive game in which a player
  attempts to label a given image presented by the
  system to match any label given by his online
  partner within a predefined time limit.

• Automatic Image Annotation
• requires
• Training the annotation system
• Analyzing and transforming training images into
  feature vectors
• Capturing relationships by probabilistic models
  

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game mechanism

• Game Actions
• Flip
• Slap
• Object
• Trap

• Scoring Mechanism
• A player gets points
• First to slap without drawing any objection.
• First to object without falling into a trap.
• Another player slaps on the trap he/she sets.

• A player loses points
• First to object and fall into the trap.
• No player slaps on the trap he/she sets.

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game strategy analysis
Subgame
the expected payoff for player 3 Ptrap (-
Strapped) (1 - Ptrap) Sobject player 3 should
object if Ptrap lt Sobject/ (Sobject Strapped)
The target strategy
Game tree of the trap stage
Game tree of the game stage
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subgame perfect equilibrium
depends on his/her belief about
action of Player 1
depends on his/her belief about
action of Player 2
Action of Player 3
depends on his/her belief about
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gameplay

• gameplay is all the activities and strategies
  game designers employ to get and keep players
  engaged (Prensky 2002) that promote deep and
  persistent engagement.
• The core elements of gameplay in PhotoSlap are
• Pattern-recognition challenge
• Reaction time challenge
• PhotoSlap is designed to be self-adaptive in
  that the competitors are carefully chosen so that
  the difficulty of challenges, the competitors
  reaction time, and their ability can be balanced
  to enable them to stay in the flow state.
• The appearance of a matching pair is dynamically
  adjusted to follow a tension curve that has
  proper frequent peaks p(t) N e (gt) .

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system overview
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evaluation
Is the game fun? PhotoSlap received an average
score of 7.6 points on a 10-point scale.
Is the game productive? productivity of the game
is measured by the links being built and the
percentage of the correct links. each game can
produce 12.3 links per minute and 98.31 of them
are correct.
How good is the game strategy?
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do you want more ?
Paparas, D. 2008 ????st??? ?p??es? F??t??? ?p?
s?????e? ?e????? G??s??. ?µ?µa ?????f?????? ?a?
???ep?????????? ???? von Ahn, L., and Dabbish,
L. 2004 Labeling images with a computer game. In
Proc. CHI 04, 319326. ACMPress. Ting-hsiang
Huang Jane Yung-jen Hsu Beyond Memories Weaving
Photos into Personal Social Networks