Abstract
Traditionally, collaborative filtering (CF) algorithms used for recommendation operate on complete knowledge. This makes these algorithms hard to employ in a decentralized context where not all users' ratings can be available at all locations. In this paper we investigate how the well-known neighbourhood-based CF algorithm by Herlocker et al. operates on partial knowledge; that is, how many similar users does the algorithm actually need to produce good recommendations for a given user, and how similar must those users be. We show for the popular MovieLens 1,000,000 and Jester datasets that sufficiently good recommendations can be made based on the ratings of a neighbourhood consisting of a relatively small number of randomly selected users.
Original language | English |
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Title of host publication | CNIKM '09 |
Subtitle of host publication | Proceedings of the 1st ACM International Workshop on Complex Networks in Information and Knowledge Management (CNIKM 2009) |
Place of Publication | New York, NY |
Publisher | ACM Publishing |
Pages | 67-74 |
Number of pages | 8 |
ISBN (Print) | 978-1-60558-807-0 |
DOIs | |
Publication status | Published - 1 Dec 2009 |
Externally published | Yes |
Event | 1st ACM International Workshop on Complex Networks in Information and Knowledge Management, , CNIKM'09 - Hong Kong, China Duration: 6 Nov 2009 → 6 Nov 2009 |
Conference
Conference | 1st ACM International Workshop on Complex Networks in Information and Knowledge Management, , CNIKM'09 |
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Country/Territory | China |
City | Hong Kong |
Period | 6/11/09 → 6/11/09 |
Other | Co-located with the 18th ACM International Conference on Information and Knowledge Management, CIKM 2009 |
Keywords
- Collaborative filtering
- Metrics
- Peer-to-peer networking
- Recommender systems