26,376 research outputs found
Evaluating the effectiveness of explanations for recommender systems : Methodological issues and empirical studies on the impact of personalization
Peer reviewedPostprin
Dancing to the Partisan Beat: A First Analysis of Political Communication on TikTok
TikTok is a video-sharing social networking service, whose popularity is
increasing rapidly. It was the world's second-most downloaded app in 2019.
Although the platform is known for having users posting videos of themselves
dancing, lip-syncing, or showcasing other talents, user-videos expressing
political views have seen a recent spurt. This study aims to perform a primary
evaluation of political communication on TikTok. We collect a set of US
partisan Republican and Democratic videos to investigate how users communicated
with each other about political issues. With the help of computer vision,
natural language processing, and statistical tools, we illustrate that
political communication on TikTok is much more interactive in comparison to
other social media platforms, with users combining multiple information
channels to spread their messages. We show that political communication takes
place in the form of communication trees since users generate branches of
responses to existing content. In terms of user demographics, we find that
users belonging to both the US parties are young and behave similarly on the
platform. However, Republican users generated more political content and their
videos received more responses; on the other hand, Democratic users engaged
significantly more in cross-partisan discussions.Comment: Accepted as a full paper at the 12th International ACM Web Science
Conference (WebSci 2020). Please cite the WebSci version; Second version
includes corrected typo
Herding Effect based Attention for Personalized Time-Sync Video Recommendation
Time-sync comment (TSC) is a new form of user-interaction review associated
with real-time video contents, which contains a user's preferences for videos
and therefore well suited as the data source for video recommendations.
However, existing review-based recommendation methods ignore the
context-dependent (generated by user-interaction), real-time, and
time-sensitive properties of TSC data. To bridge the above gaps, in this paper,
we use video images and users' TSCs to design an Image-Text Fusion model with a
novel Herding Effect Attention mechanism (called ITF-HEA), which can predict
users' favorite videos with model-based collaborative filtering. Specifically,
in the HEA mechanism, we weight the context information based on the semantic
similarities and time intervals between each TSC and its context, thereby
considering influences of the herding effect in the model. Experiments show
that ITF-HEA is on average 3.78\% higher than the state-of-the-art method upon
F1-score in baselines.Comment: ACCEPTED for ORAL presentation at IEEE ICME 201
Hierarchical Exploration for Accelerating Contextual Bandits
Contextual bandit learning is an increasingly popular approach to optimizing
recommender systems via user feedback, but can be slow to converge in practice
due to the need for exploring a large feature space. In this paper, we propose
a coarse-to-fine hierarchical approach for encoding prior knowledge that
drastically reduces the amount of exploration required. Intuitively, user
preferences can be reasonably embedded in a coarse low-dimensional feature
space that can be explored efficiently, requiring exploration in the
high-dimensional space only as necessary. We introduce a bandit algorithm that
explores within this coarse-to-fine spectrum, and prove performance guarantees
that depend on how well the coarse space captures the user's preferences. We
demonstrate substantial improvement over conventional bandit algorithms through
extensive simulation as well as a live user study in the setting of
personalized news recommendation.Comment: Appears in Proceedings of the 29th International Conference on
Machine Learning (ICML 2012
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