Title
LookOut on Time-Evolving Graphs: Succinctly Explaining Anomalies from Any Detector.
Abstract
Why is a given node in a time-evolving graph ($t$-graph) marked as an anomaly by an off-the-shelf detection algorithm? Is it because of the number of its outgoing or incoming edges, or their timings? How can we convince a human analyst that the node is anomalous? Our work aims to provide succinct, interpretable, and simple explanations of anomalous behavior in $t$-graphs (communications, IP-IP interactions, etc.) while respecting the limited attention of human analysts. Specifically, we extract key features from such graphs, and propose to output a few pair (scatter) plots from this feature space which best explain known anomalies. To this end, our work has four main contributions: (a) problem formulation: we introduce an analyst-friendly problem formulation for explaining anomalies via pair plots, (b) explanation algorithm: we propose a plot-selection objective and the LookOut algorithm to approximate it with optimality guarantees, (c) generality: our explanation algorithm is both domain- and detector-agnostic, and (d) scalability: we show that LookOut scales linearly on the number of edges of the input graph. Our experiments show that LookOut performs near-ideally in terms of maximizing explanation objective on several real datasets including Enron e-mail and DBLP coauthorship. Furthermore, LookOut produces fast, visually interpretable and intuitive results in explaining ground-truth anomalies from Enron, DBLP and LBNL (computer network) data.
Year
Venue
Field
2017
arXiv: Social and Information Networks
Graph,Data mining,Feature vector,Computer science,Theoretical computer science,Detector,Generality,Scalability,Anomalous behavior
DocType
Volume
Citations 
Journal
abs/1710.05333
0
PageRank 
References 
Authors
0.34
14
5
Name
Order
Citations
PageRank
Nikhil Gupta101.69
Dhivya Eswaran2274.27
Neil Shah302.37
Leman Akoglu4149871.55
Christos Faloutsos5279724490.38