PARL: Let Strangers Speak Out What You Like
Libing Wu
1
, Cong Quan
1
, Chenliang Li
2⋆
, Donghong Ji
2
1. School of Computer Science, Wuhan University, Wuhan, 430072, China
{wu, quancong}@whu.edu.cn
2. School of Cyber Science and Engineering, Wuhan University, Wuhan, 430072, China
{cllee, dhji}@whu.edu.cn
ABSTRACT
Review-based methods are one of the dominant methods to address
the data sparsity problem of recommender system. However, the
performance of most existing review-based methods will degrade
when the review is also sparse. To this end, we propose a method to
exploit user-item
p
air-dependent features from
a
uxiliary
r
eviews
written by
l
ike-minded users (PARL) to address such problem. That
is, both the reviews written by the user and the reviews written
for the item are incorporated to highlight the useful features cov-
ered by the auxiliary reviews. PARL not only alleviates the sparsity
problem of reviews but also produce extra informative features
to further improve the accuracy of rating prediction. More impor-
tantly, it is designed as a plug-and-play model which can be plugged
into various deep recommender systems to improve recommenda-
tions provided by them. Extensive experiments on ve real-world
datasets show that PARL achieves better prediction accuracy than
other state-of-the-art alternatives. Also, with the exploitation of
auxiliary reviews, the performance of PARL is robust on datasets
with dierent characteristics.
CCS CONCEPTS
• Information systems → Recommender systems;
KEYWORDS
Recommender System, User Reviews, Deep Learning, Rating Pre-
diction
ACM Reference Format:
Libing Wu, Cong Quan, Chenliang Li, Donghong Ji. 2018. PARL: Let Strangers
Speak Out What You Like. In 2018 ACM Conference on Information and
Knowledge Management (CIKM’18), October 22–26, 2018, Torino, Italy.
ACM, NY, NY, USA, 10 pages. https://doi.org/10.1145/3269206.3271695
1 INTRODUCTION
In the past decade, Recommender Systems have been playing an
increasingly important role in many online platforms, including
E-commerce such as Amazon, video-streaming providers such as
⋆
Chenliang Li is the corresponding author.
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CIKM ’18, October 22–26, 2018, Torino, Italy
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https://doi.org/10.1145/3269206.3271695
Figure 1: Examples of reviews written by two audiences for
the lm “Innite War” on IMDB. Both users give the highest
rate to Innite War, and similar interests are presented by
their reviews.
Youtube and social media such as Twitter. The key to a recom-
mender system is to dig out user’s interest and thus personalized
recommendation can be provided.
Many recommender systems are based on Collaborative Filtering
(CF) [
29
], which mainly rely on the past interaction records between
users and items. Although CF techniques enjoy a surge of atten-
tion and provide good performance, the sparsity problem hinders
the CF-based recommender systems from providing high-quality
recommendations to the users with few records. In this case, neigh-
borhood methods [
11
] are employed to alleviate the data sparsity
problem. Concretely, neighborhood methods utilize the relations
between items or between users to improve the recommendation.
For example, a neighborhood-based method [
2
] estimates an un-
kown rating on an item made by a user based on the known ratings
made by the same user on other items.
Recently, some approaches also resort to reviews written by
users to address the lack of data. The motivation is that ratings and
review are two facets of users to depict their experience on items.
Therefore, the reviews can be used to well alleviate data sparsity.
Some studies [
20
,
37
] have shown that methods considering reviews
generally perform better than collaborative ltering methods which
only take the interaction records into consideration. In particular,
the performance of review-based methods is robust when the users
Session 4E: Recommendation 1
CIKM’18, October 22-26, 2018, Torino, Italy