59 research outputs found
Evaluation of recommender systems in streaming environments
Evaluation of recommender systems is typically done with finite datasets.
This means that conventional evaluation methodologies are only applicable in
offline experiments, where data and models are stationary. However, in real
world systems, user feedback is continuously generated, at unpredictable rates.
Given this setting, one important issue is how to evaluate algorithms in such a
streaming data environment. In this paper we propose a prequential evaluation
protocol for recommender systems, suitable for streaming data environments, but
also applicable in stationary settings. Using this protocol we are able to
monitor the evolution of algorithms' accuracy over time. Furthermore, we are
able to perform reliable comparative assessments of algorithms by computing
significance tests over a sliding window. We argue that besides being suitable
for streaming data, prequential evaluation allows the detection of phenomena
that would otherwise remain unnoticed in the evaluation of both offline and
online recommender systems.Comment: Workshop on 'Recommender Systems Evaluation: Dimensions and Design'
(REDD 2014), held in conjunction with RecSys 2014. October 10, 2014, Silicon
Valley, United State
Synthetic sequence generator for recommender systems - memory biased random walk on sequence multilayer network
Personalized recommender systems rely on each user's personal usage data in
the system, in order to assist in decision making. However, privacy policies
protecting users' rights prevent these highly personal data from being publicly
available to a wider researcher audience. In this work, we propose a memory
biased random walk model on multilayer sequence network, as a generator of
synthetic sequential data for recommender systems. We demonstrate the
applicability of the synthetic data in training recommender system models for
cases when privacy policies restrict clickstream publishing.Comment: The new updated version of the pape
Report on RecSys 2015 Workshop on New Trends in Content-Based Recommender Systems (CBRecSys 2015)
This article reports on the CBRecSys 2015 workshop, the second edition of the workshop on new trends in content-based recommender systems, co-located with RecSys 2015 in Vienna, Austria. Content-based recommendation has been applied successfully in many different domains, but it has not seen the same level of attention as collaborative filtering techniques have. Nevertheless, there are many recommendation domains and applications where content and metadata play a key role, either in addition to or instead of ratings and implicit usage data. The CBRecSys workshop series provides a dedicated venue for work dedicated to all aspects of content-based recommender systems.</jats:p
A large multilingual and multi-domain dataset for recommender systems
This paper presents a multi-domain interests dataset to train and test Recommender Systems, and the methodology to create the dataset
from Twitter messages in English and Italian. The English dataset includes an average of 90 preferences per user on music, books,
movies, celebrities, sport, politics and much more, for about half million users. Preferences are either extracted from messages of
users who use Spotify, Goodreads and other similar content sharing platforms, or induced from their ”topical” friends, i.e., followees
representing an interest rather than a social relation between peers. In addition, preferred items are matched with Wikipedia articles
describing them. This unique feature of our dataset provides a mean to derive a semantic categorization of the preferred items, exploiting
available semantic resources linked to Wikipedia such as the Wikipedia Category Graph, DBpedia, BabelNet and others
Feature-Based Matrix Factorization
Recommender system has been more and more popular and widely used in many
applications recently. The increasing information available, not only in
quantities but also in types, leads to a big challenge for recommender system
that how to leverage these rich information to get a better performance. Most
traditional approaches try to design a specific model for each scenario, which
demands great efforts in developing and modifying models. In this technical
report, we describe our implementation of feature-based matrix factorization.
This model is an abstract of many variants of matrix factorization models, and
new types of information can be utilized by simply defining new features,
without modifying any lines of code. Using the toolkit, we built the best
single model reported on track 1 of KDDCup'11.Comment: Minor update, add some related work
- …