Title
Sparse Learning-to-Rank via an Efficient Primal-Dual Algorithm
Abstract
Learning-to-rank for information retrieval has gained increasing interest in recent years. Inspired by the success of sparse models, we consider the problem of sparse learning-to-rank, where the learned ranking models are constrained to be with only a few nonzero coefficients. We begin by formulating the sparse learning-to-rank problem as a convex optimization problem with a sparse-inducing ℓ1 constraint. Since the ℓ1 constraint is nondifferentiable, the critical issue arising here is how to efficiently solve the optimization problem. To address this issue, we propose a learning algorithm from the primal dual perspective. Furthermore, we prove that, after at most O(1/ε) iterations, the proposed algorithm can guarantee the obtainment of an ε-accurate solution. This convergence rate is better than that of the popular subgradient descent algorithm. i.e., O(1/ε2). Empirical evaluation on several public benchmark data sets demonstrates the effectiveness of the proposed algorithm: 1) Compared to the methods that learn dense models, learning a ranking model with sparsity constraints significantly improves the ranking accuracies. 2) Compared to other methods for sparse learning-to-rank, the proposed algorithm tends to obtain sparser models and has superior performance gain on both ranking accuracies and training time. 3) Compared to several state-of-the-art algorithms, the ranking accuracies of the proposed algorithm are very competitive and stable.
Year
DOI
Venue
2013
10.1109/TC.2012.62
IEEE Trans. Computers
Keywords
Field
DocType
subgradient descent algorithm,ranking accuracy improvement,performance gain,state-of-the-art algorithm,convex optimization problem,fenchel duality,sparse-inducing l1 constraint,learning (artificial intelligence),primal-dual algorithm,ranking model,information retrieval,ranking accuracy,convex programming,nonzero coefficients,sparse model,dense model learning,optimization problem,sparse learning-to-rank problem,proposed algorithm,gradient methods,learned ranking models,sparse models,sparse learning-to-rank,ranking algorithm,efficient primal-dual algorithm,popular subgradient descent algorithm,sparsity constraints,learning-to-rank,learning algorithm,vectors,accuracy,prediction algorithms,computational modeling,optimization,support vector machines,learning artificial intelligence,learning to rank
Learning to rank,Diffusing update algorithm,Mathematical optimization,Ranking SVM,Ranking,Subgradient method,Computer science,Support vector machine,Convex optimization,Optimization problem
Journal
Volume
Issue
ISSN
62
6
0018-9340
Citations 
PageRank 
References 
25
0.78
21
Authors
5
Name
Order
Citations
PageRank
Hanjiang Lai123417.67
Yan Pan217919.23
Cong Liu358630.47
Liang Lin43007151.07
Jie Wu58307592.07