Our SAGs: Design Aspects and Improvements - Semantic Acquisition Games: Harnessing Manpower for Creating Semantics - page 120

instances solved in a single man-hour of playing). The attractiveness is an expression
of howmuch people like the game, more rigidly: howmuch man-hours of playing we
could possibly harness. The attractiveness is determined with two aspects of a SAG:
ability to attract and ability to keep the attention of the player. It is also important to
track the ability of the game to spread virally (since we have no capacity to propagate
the game in a greater scale). We conducted a player survey, in which we asked [ 5 ]:

￿ If and how the players understood the game principles and purpose (the ability of

attracting the attention is strongly influenced by this).

￿ If they would play again (the ability to keep player's attention) and if they would

recommend it to a friend (effectively the ability of viral spreading).

￿ If they were somehow convinced with the “greater good” of the game to play it.

Results of the questionnaire showed that the game is not self-explaining enough
(many players answered that they needed to consult the manual or the game author
in order to understand the game). This means the lack of ability to attract attention.
On the other hand, the game was liked by 80% of players and almost one third of
themwould spread it virally. Also the interesting result is that 1/6 of the players were
actually convinced by the game purpose to play (which supports the notion that the
game purpose has to be known to the players). Results of the questionnaire leaves
the attraction problem open, but encourages to continue on this project.

8.2 PexAce

From the SAG design point of view, the PexAce is a demonstration of a game,
which motivates players to create useful artifacts but does not require immediate
evaluation of these artifacts after the game session to provide score. It therefore can
remain single-player and require no control data set for bootstrapping as other games
need to [ 3 , 6 ]. In addition, the PexAce-Personal modification of the game applies an
unique player motivation—option to use the “purposeful output” (the image tags) of
the game for himself. Moreover, with PexAce, we demonstrate the potential of using
the information about player expertise to improve quality of its output metadata. As
well as other games, PexAce too was under threat of malicious player behavior. Thus
we were also forced to improve the game in this way, mixing the prevention with
a posteriori cheating detection.

8.2.1 Helper Artifacts: A Novel Approach for Artifact Validation

Being a semantics acquisition game, the PexAce has an unusual scoring mechanism
which is not dependent on the actual quality of the artifacts (image annotations)
that player is creating within the game. In fact, the player can completely omit the
annotations and rely on his memory only. He is scored only according to the time he
need for the game and (more importantly) the number of flips hemakes. Nevertheless,