Our SAGs: Design Aspects and Improvements - Semantic Acquisition Games: Harnessing Manpower for Creating Semantics - page 123

the true reason why we do not rely on the competitive aspect of the PexAce-personal.
Due to the fact that participation on a consensus could not be measured (as much of
the metadata is provided by solo players and validated other way), the a posteriori
anti-cheating is also short handed. Therefore, we decided to remove the reason for
cheating, the global score ladder.
This removes much of the competitive motivation to play. Not entire though: we
still see the possibility to organize competition among social circles of the players
(which is common in many social games on theWeb). If the circles are based on a real
social bonds, then the sense of fair play is much more greater and potential cheaters
discouraged. The community can also watch over itself: the individual players may
(from time to time) peer-review the annotations and images of their opponents and
report abuses so they are visible to the community.
Much of the motivation in PexAce-Personal is done by other than competitive
incentives. The first one is somewhat similar to the general version of the game, yet
much stronger: joy of viewing one's own images (or images of one's social circle). It
is the same incentive that motivates people to review their photo albums from time
to time: they like to refresh and “replay” their memories. Secondly, there is a very
important incentive why to play the PexAce-Personal: working for one's own sake ,
i.e. organizing one's own image repository with the metadata created in the game.
None of the latter two motivations can really be categorized using the SAG
design aspects system we described in this work (categories social experience, self-
challenge, competition and discovery), simply because they are not present in any
other SAGs.
On the contrary, we claim them as a contribution to the SAG design field. No other
SAG before has used this type of motivation. We believe that combining working for
one's own sake with other types of gameplay motivations in a SAGmay dramatically
boost its potential. Of course, it limits the use only for certain domains resp. problems
(e.g. multimedia resource description), but this is still very wide. Especially if we
recognize that the artifacts produced by players under these conditions have better
quality (as we have shown in the experiments).
8.2.3 Player Competences
In PexAce, we have also experimented with recognizing player competences and
using them for improving the game's output.
8.2.3.1 Recognizing Competences: A General Motivation
SAG players are not equal in terms of their knowledge. Therefore, the value (of
artifacts) they deliver differs according to the tasks they solve. In semantics acquisi-
tion, these differences are mostly apparent across domains (an expert on the classical
music may perform bad in case of techno in a music tagging game). They are also