This paper investigates an active learning (AL) [21], [27]
approach for streaming data to maintain an on-line model that
is robust to class imbalances. The principle is to query only
a fraction of the labels, usually just the most informative data
near the decision boundary, and thereby to attain an accurate
classifier at significantly lower cost than regular supervised
learning. To the best of our knowledge our work is the first to
use active learning for PD classification [19].