Title
A tale of two metrics: simultaneous bounds on competitiveness and regret
Abstract
We consider algorithms for "smoothed online convex optimization" problems, a variant of the class of online convex optimization problems that is strongly related to metrical task systems. Prior literature on these problems has focused on two performance metrics: regret and the competitive ratio. There exist known algorithms with sublinear regret and known algorithms with constant competitive ratios; however, no known algorithm achieves both simultaneously. We show that this is due to a fundamental incompatibility between these two metrics - no algorithm (deterministic or randomized) can achieve sublinear regret and a constant competitive ratio, even in the case when the objective functions are linear. However, we also exhibit an algorithm that, for the important special case of one-dimensional decision spaces, provides sublinear regret while maintaining a competitive ratio that grows arbitrarily slowly.
Year
DOI
Venue
2013
10.1145/2465529.2465533
SIGMETRICS
Keywords
Field
DocType
simultaneous bound,learning theory,online algorithms
Metrical task system,Sublinear function,Online algorithm,Mathematical optimization,Regret,Computer science,Performance metric,Convex optimization,Competitive analysis
Conference
Volume
Issue
ISSN
abs/1508.03769
1
0163-5999
Citations 
PageRank 
References 
23
1.04
29
Authors
7
Name
Order
Citations
PageRank
L. L.H. Andrew191852.52
Siddharth Barman219926.26
Katrina Ligett392366.19
Minghong Lin444416.14
Adam Meyerson52132146.08
Alan Roytman6937.52
Adam Wierman71635106.57