Title
Top-N recommendations in the presence of sparsity: An NCD-based approach.
Abstract
Making recommendations in the presence of sparsity is known to present one of the most challenging problems faced by collaborative filtering methods. In this work we tackle this problem by exploiting the innately hierarchical structure of the item space following an approach inspired by the theory of Decomposability. We view the itemspace as a Nearly Decomposable system and we define blocks of closely related elements and corresponding indirect proximity components. We study the theoretical properties of the decomposition and we derive sufficient conditions that guarantee full item space coverage even in cold-start recommendation scenarios. A comprehensive set of experiments on the MovieLens and the Yahoo!R2Music datasets, using several widely applied performance metrics, support our model's theoretically predicted properties and verify that NCDREC outperforms several state-of-the-art algorithms, in terms of recommendation accuracy, diversity and sparseness insensitivity.
Year
DOI
Venue
2015
10.3233/WEB-150324
WEB INTELLIGENCE
Keywords
Field
DocType
Recommender systems,collaborative filtering,sparsity,decomposability,Markov chain models,long-tail recommendation
Recommender system,Data mining,Collaborative filtering,Computer science,MovieLens,Artificial intelligence,Machine learning
Journal
Volume
Issue
ISSN
13
4
2405-6456
Citations 
PageRank 
References 
0
0.34
28
Authors
2
Name
Order
Citations
PageRank
Athanasios N. Nikolakopoulos1599.02
John D. Garofalakis217636.73