TY  - RPRT
ID  - jf:TUD-KE-2007-04
T1  - On Minimizing the Position Error in Label Ranking
A1  - Hüllermeier, Eyke
A1  - Fürnkranz, Johannes
Y1  - 2007
IS  - TUD-KE-2007-04
T2  - TU Darmstadt, Knowledge Engineering Group
UR  - /publications/reports/tud-ke-2007-04.pdf
N2  - Conventional classification learning allows a classifier to make a one shot decision in
order to identify the correct label. However, in many practical applications, the problem is
not to give a single estimation, but to make repeated suggestions until the correct target
label has been identified. Thus, the learner has to deliver a label ranking, that is, a ranking
of all possible alternatives. In this paper, we discuss a loss function, called the position
error, which is suitable for evaluating the performance of a label ranking algorithm in this
setting. Moreover, we propose “ranking through iterated choice”, a general strategy for
extending any multi-class classifier to this scenario. Its basic idea is to reduce label ranking
to standard classification by successively predicting a most likely class label and retraining
a model on the remaining classes. We demonstrate empirically that this procedure does
indeed reduce the position error in comparison with a conventional approach that ranks
the classes according to their estimated probabilities. Besides, we also address the issue of
implementing ranking through iterated choice in a computationally efficient way.
ER  -