10 research outputs found
News Session-Based Recommendations using Deep Neural Networks
News recommender systems are aimed to personalize users experiences and help
them to discover relevant articles from a large and dynamic search space.
Therefore, news domain is a challenging scenario for recommendations, due to
its sparse user profiling, fast growing number of items, accelerated item's
value decay, and users preferences dynamic shift. Some promising results have
been recently achieved by the usage of Deep Learning techniques on Recommender
Systems, specially for item's feature extraction and for session-based
recommendations with Recurrent Neural Networks. In this paper, it is proposed
an instantiation of the CHAMELEON -- a Deep Learning Meta-Architecture for News
Recommender Systems. This architecture is composed of two modules, the first
responsible to learn news articles representations, based on their text and
metadata, and the second module aimed to provide session-based recommendations
using Recurrent Neural Networks. The recommendation task addressed in this work
is next-item prediction for users sessions: "what is the next most likely
article a user might read in a session?" Users sessions context is leveraged by
the architecture to provide additional information in such extreme cold-start
scenario of news recommendation. Users' behavior and item features are both
merged in an hybrid recommendation approach. A temporal offline evaluation
method is also proposed as a complementary contribution, for a more realistic
evaluation of such task, considering dynamic factors that affect global
readership interests like popularity, recency, and seasonality. Experiments
with an extensive number of session-based recommendation methods were performed
and the proposed instantiation of CHAMELEON meta-architecture obtained a
significant relative improvement in top-n accuracy and ranking metrics (10% on
Hit Rate and 13% on MRR) over the best benchmark methods.Comment: Accepted for the Third Workshop on Deep Learning for Recommender
Systems - DLRS 2018, October 02-07, 2018, Vancouver, Canada.
https://recsys.acm.org/recsys18/dlrs
Fine-Grained Session Recommendations in E-commerce using Deep Reinforcement Learning
Sustaining users' interest and keeping them engaged in the platform is very
important for the success of an e-commerce business. A session encompasses
different activities of a user between logging into the platform and logging
out or making a purchase. User activities in a session can be classified into
two groups: Known Intent and Unknown intent. Known intent activity pertains to
the session where the intent of a user to browse/purchase a specific product
can be easily captured. Whereas in unknown intent activity, the intent of the
user is not known. For example, consider the scenario where a user enters the
session to casually browse the products over the platform, similar to the
window shopping experience in the offline setting. While recommending similar
products is essential in the former, accurately understanding the intent and
recommending interesting products is essential in the latter setting in order
to retain a user. In this work, we focus primarily on the unknown intent
setting where our objective is to recommend a sequence of products to a user in
a session to sustain their interest, keep them engaged and possibly drive them
towards purchase. We formulate this problem in the framework of the Markov
Decision Process (MDP), a popular mathematical framework for sequential
decision making and solve it using Deep Reinforcement Learning (DRL)
techniques. However, training the next product recommendation is difficult in
the RL paradigm due to large variance in browse/purchase behavior of the users.
Therefore, we break the problem down into predicting various product
attributes, where a pattern/trend can be identified and exploited to build
accurate models. We show that the DRL agent provides better performance
compared to a greedy strategy
Recommending Target Actions Outside Sessions in the Data-poor Insurance Domain
Providing personalized recommendations for insurance products is particularly
challenging due to the intrinsic and distinctive features of the insurance
domain. First, unlike more traditional domains like retail, movie etc., a large
amount of user feedback is not available and the item catalog is smaller.
Second, due to the higher complexity of products, the majority of users still
prefer to complete their purchases over the phone instead of online. We present
different recommender models to address such data scarcity in the insurance
domain. We use recurrent neural networks with 3 different types of loss
functions and architectures (cross-entropy, censored Weibull, attention). Our
models cope with data scarcity by learning from multiple sessions and different
types of user actions. Moreover, differently from previous session-based
models, our models learn to predict a target action that does not happen within
the session. Our models outperform state-of-the-art baselines on a real-world
insurance dataset, with ca. 44K users, 16 items, 54K purchases and 117K
sessions. Moreover, combining our models with demographic data boosts the
performance. Analysis shows that considering multiple sessions and several
types of actions are both beneficial for the models, and that our models are
not unfair with respect to age, gender and income.Comment: arXiv admin note: substantial text overlap with arXiv:2211.1536
A Taxonomy of Sequential Patterns Based Recommendation Systems
With remarkable expansion of information through the internet, users prefer to receive the exact information they need through some suggestions to save their time and money. Thus, recommendation systems have become the heart of business strategies of E-commerce as they can increase sales and revenue as well as customer loyalty. Recommendation systems techniques provide suggestions for items/products to be purchased, rented or used by a user. The most common type of recommendation system technique is Collaborative Filtering (CF), which takes user’s interest in an item (explicit rating) as input in a matrix known as the user-item rating matrix, and produces an output for unknown ratings of users for items from which top N recommended items for target users are defined. E-commerce recommendation systems usually deal with massive customer sequential databases such as historical purchase or click sequences. The time stamp of a click or purchase event is an important attribute of each dataset as the time interval between item purchases may be useful to learn the next items for purchase by users. Sequential Pattern Mining mines frequent or high utility sequential patterns from a sequential database. Recommendation systems accuracy will be improved if complex sequential patterns of user purchase behavior are learned by integrating sequential patterns of customer clicks and/or purchases into the user-item rating matrix input. Thus, integrating collaborative filtering (CF) and sequential pattern mining (SPM) of historical clicks and purchase data can improve recommendation accuracy, diversity and quality and this survey focuses on review of existing recommendation systems that are sequential pattern based exposing their methodologies, achievements, limitations, and potentials for solving more problems in this domain. This thesis provides a comprehensive and comparative study of the existing Sequential Pattern-based E-commerce recommendation systems (SP-based E-commerce RS) such as ChoRec05, ChenRec09, HuangRec09, LiuRec09, ChoiRec12, Hybrid Model RecSys16, Product RecSys16, SainiRec17, HPCRec18 and HSPCRec19. Thesis shows that integrating sequential patterns mining (SPM) of historical purchase and/or click sequences into user-item matrix for collaborative filtering (CF) (i) Improved recommendation accuracy (ii) Reduced limiting user-item rating data Sparsity (iii) Increased Novelty Rate of the recommendations and (iv) Improved Scalability of the recommendation system. Thus, the importance of sequential patterns of customer behavior in improving the quality of recommendation systems for the application domain of E-commerce is accentuated through this survey by having a comparative performance analysis of the surveyed systems