In this paper, we describe the challenges inherent to the task of  link prediction , and we analyze one reason why many link prediction models perform poorly. Specifically, we demonstrate the effects of the extremely large class skew associated with the link prediction task. We then present an alternate task ---  anomalous link discovery  (ALD) --- and qualitatively demonstrate the effectiveness of simple link prediction models for the ALD task. We show that even the simplistic structural models that perform poorly on link prediction can perform quite well at the ALD task.
['Matthew J. Rattigan', 'David D. Jensen']
The case for anomalous link discovery