CityLights: A Method for Music Metadata Validation - Semantic Acquisition Games: Harnessing Manpower for Creating Semantics - page 83

Fig. 6.3 The CityLights game interface after the correct pick. The player just explicitly ruled out
two tags that he considered invalid

• After a “correct” choice pick, the player can mark a tag (or more) within the

“correct” choice tag set that he considers being wrong or of no value (see Fig. 6.3 ).
The player is rewarded by a constant minor point gain (regardless on the number
of tags he rules-out). The constant value is to reduce the motivation to abuse this
feature to gain more points. Secondly, we also motivate the player to rule-out the
tags correctly: the tags he rules out will not appear in the game for the current music
track anymore for that player (the player may encounter the track more times).
Therefore, a correct “cleansing” of the tag sets is also in the player's interest.

•

After an incorrect choice pick, the player can mark tags within the selected choice
which convinced him to guess wrongly. Later, these tags may become candidates
to be added to the description of the played track, even if they were not present
there in the input set. (In the current implementation of the CityLights, we have
not included this option—it is a subject for future work).

Tag buying

Another minor feature of the CityLights is the so called tag buying . In the game, play-
ers often hesitate between several choices or are unable to assign any of the choices
with the currently playing music. In both cases, this means that the quality of tags
in the “correct” choice might not be ideal. It is therefore convenient to measure this
type of feedback. Even though the player “hesitation” could be implicitly assessed
by measuring the time between the question stating and answering, we came up with
a more explicit form of feedback.