A Latent Source Model for Online Collaborative Filtering

Despite the prevalence of collaborative filtering in recommendation systems, there has been little theoretical development on why and how well it works, especially in the “online” setting, where items are recommended to users over time. We address this theoretical gap by introducing a model for onli...

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Main Authors: Bresler, Guy, Chen, George, Shah, Devavrat
Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Format: Article
Language:en_US
Published: Neural Information Processing Systems Foundation, Inc. 2014
Online Access:http://hdl.handle.net/1721.1/91678
https://orcid.org/0000-0003-0737-3259
https://orcid.org/0000-0003-1303-582X
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author Bresler, Guy
Chen, George
Shah, Devavrat
author2 Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
author_facet Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Bresler, Guy
Chen, George
Shah, Devavrat
author_sort Bresler, Guy
collection MIT
description Despite the prevalence of collaborative filtering in recommendation systems, there has been little theoretical development on why and how well it works, especially in the “online” setting, where items are recommended to users over time. We address this theoretical gap by introducing a model for online recommendation systems, cast item recommendation under the model as a learning problem, and analyze the performance of a cosine-similarity collaborative filtering method. In our model, each of n users either likes or dislikes each of m items. We assume there to be k types of users, and all the users of a given type share a common string of probabilities determining the chance of liking each item. At each time step, we recommend an item to each user, where a key distinction from related bandit literature is that once a user consumes an item (e.g., watches a movie), then that item cannot be recommended to the same user again. The goal is to maximize the number of likable items recommended to users over time. Our main result establishes that after nearly log(km) initial learning time steps, a simple collaborative filtering algorithm achieves essentially optimal performance without knowing k. The algorithm has an exploitation step that uses cosine similarity and two types of exploration steps, one to explore the space of items (standard in the literature) and the other to explore similarity between users (novel to this work).
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spelling mit-1721.1/916782022-09-28T13:51:43Z A Latent Source Model for Online Collaborative Filtering Bresler, Guy Chen, George Shah, Devavrat Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Laboratory for Information and Decision Systems Bresler, Guy Chen, George Shah, Devavrat Despite the prevalence of collaborative filtering in recommendation systems, there has been little theoretical development on why and how well it works, especially in the “online” setting, where items are recommended to users over time. We address this theoretical gap by introducing a model for online recommendation systems, cast item recommendation under the model as a learning problem, and analyze the performance of a cosine-similarity collaborative filtering method. In our model, each of n users either likes or dislikes each of m items. We assume there to be k types of users, and all the users of a given type share a common string of probabilities determining the chance of liking each item. At each time step, we recommend an item to each user, where a key distinction from related bandit literature is that once a user consumes an item (e.g., watches a movie), then that item cannot be recommended to the same user again. The goal is to maximize the number of likable items recommended to users over time. Our main result establishes that after nearly log(km) initial learning time steps, a simple collaborative filtering algorithm achieves essentially optimal performance without knowing k. The algorithm has an exploitation step that uses cosine similarity and two types of exploration steps, one to explore the space of items (standard in the literature) and the other to explore similarity between users (novel to this work). National Science Foundation (U.S.) (Grant CNS-1161964) United States. Army Research Office. Multidisciplinary University Research Initiative (Award W911NF-11-1-0036) American Society for Engineering Education. National Defense Science and Engineering Graduate Fellowship 2014-11-21T16:33:23Z 2014-11-21T16:33:23Z 2014-12 Article http://purl.org/eprint/type/ConferencePaper http://hdl.handle.net/1721.1/91678 Bresler, Guy, George H. Chen, and Devavrat Shah. "A Latent Source Model for Online Collaborative Filtering." Advances in Neural Information Processing Systems 27 (NIPS 2014), pp.1-9. https://orcid.org/0000-0003-0737-3259 https://orcid.org/0000-0003-1303-582X en_US http://papers.nips.cc/paper/5330-a-latent-source-model-for-online-collaborative-filtering Proceedings of the 2014 Neural Information Processing Systems Foundation Conference (NIPS 2014) Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Neural Information Processing Systems Foundation, Inc. Chen
spellingShingle Bresler, Guy
Chen, George
Shah, Devavrat
A Latent Source Model for Online Collaborative Filtering
title A Latent Source Model for Online Collaborative Filtering
title_full A Latent Source Model for Online Collaborative Filtering
title_fullStr A Latent Source Model for Online Collaborative Filtering
title_full_unstemmed A Latent Source Model for Online Collaborative Filtering
title_short A Latent Source Model for Online Collaborative Filtering
title_sort latent source model for online collaborative filtering
url http://hdl.handle.net/1721.1/91678
https://orcid.org/0000-0003-0737-3259
https://orcid.org/0000-0003-1303-582X
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