Title
Conflict-directed relaxation of constraints in content-based recommender systems
Abstract
Content-based recommenders are systems that exploit detailed knowledge about the items in the catalog for generating adequate product proposals. In that context, query relaxation is one of the basic approaches for dealing with situations, where none of the products in the catalogue exactly matches the customer requirements. The major challenges when applying query relaxation are that the relaxation should be minimal (or optimal for the customer), that there exists a potentially vast search space, and that we have to deal with hard time constraints in interactive recommender applications. In this paper, we show how the task of finding adequate or customer optimal relaxations for a given recommendation problem can be efficiently achieved by applying techniques from the field of model-based diagnosis, i.e., with the help of extended algorithms for computing conflicts and hitting sets. In addition, we propose a best-effort search algorithm based on branch-and-bound for dealing with hard problems and also describe how an optimal relaxation can be immediately obtained when partial queries can be (pre-)evaluated. Finally, we discuss the results of an evaluation of the described techniques, which we made by extending an existing knowledge-based recommender system and which we based on different real-world problem settings.
Year
DOI
Venue
2006
10.1007/11779568_88
IEA/AIE
Keywords
Field
DocType
conflict-directed relaxation,customer optimal relaxation,hard time constraint,hard problem,different real-world problem setting,customer requirement,best-effort search algorithm,query relaxation,existing knowledge-based recommender system,optimal relaxation,adequate product proposal,content-based recommender system,branch and bound,search algorithm,best effort,knowledge base,search space,recommender system
Recommender system,Customer requirements,Data mining,Content analysis,Search algorithm,Existential quantification,Computer science,Knowledge-based systems,Model-based reasoning,Exploit,Artificial intelligence,Machine learning
Conference
Volume
ISSN
ISBN
4031
0302-9743
3-540-35453-0
Citations 
PageRank 
References 
9
0.61
12
Authors
2
Name
Order
Citations
PageRank
Dietmar Jannach11847130.74
Johannes Liegl2141.49