26,285 research outputs found
Applying Recommender Systems and Adaptive Hypermedia for e-Learning Personalizatio
Learners learn differently because they are different -- and they grow more distinctive as they mature. Personalized learning occurs when e-learning systems make deliberate efforts to design educational experiences that fit the needs, goals, talents, and interests of their learners. Researchers had recently begun to investigate various techniques to help teachers improve e-learning systems. In this paper we present our design and implementation of an adaptive and intelligent web-based programming tutoring system -- Protus, which applies recommendation and adaptive hypermedia techniques. This system aims at automatically guiding the learner's activities and recommend relevant links and actions to him/her during the learning process. Experiments on real data sets show the suitability of using both recommendation and hypermedia techniques in order to suggest online learning activities to learners based on their preferences, knowledge and the opinions of the users with similar characteristics
Fast Adaptively Weighted Matrix Factorization for Recommendation with Implicit Feedback
Recommendation from implicit feedback is a highly challenging task due to the
lack of the reliable observed negative data. A popular and effective approach
for implicit recommendation is to treat unobserved data as negative but
downweight their confidence. Naturally, how to assign confidence weights and
how to handle the large number of the unobserved data are two key problems for
implicit recommendation models. However, existing methods either pursuit fast
learning by manually assigning simple confidence weights, which lacks
flexibility and may create empirical bias in evaluating user's preference; or
adaptively infer personalized confidence weights but suffer from low
efficiency. To achieve both adaptive weights assignment and efficient model
learning, we propose a fast adaptively weighted matrix factorization (FAWMF)
based on variational auto-encoder. The personalized data confidence weights are
adaptively assigned with a parameterized neural network (function) and the
network can be inferred from the data. Further, to support fast and stable
learning of FAWMF, a new specific batch-based learning algorithm fBGD has been
developed, which trains on all feedback data but its complexity is linear to
the number of observed data. Extensive experiments on real-world datasets
demonstrate the superiority of the proposed FAWMF and its learning algorithm
fBGD
A Personalized System for Conversational Recommendations
Searching for and making decisions about information is becoming increasingly
difficult as the amount of information and number of choices increases.
Recommendation systems help users find items of interest of a particular type,
such as movies or restaurants, but are still somewhat awkward to use. Our
solution is to take advantage of the complementary strengths of personalized
recommendation systems and dialogue systems, creating personalized aides. We
present a system -- the Adaptive Place Advisor -- that treats item selection as
an interactive, conversational process, with the program inquiring about item
attributes and the user responding. Individual, long-term user preferences are
unobtrusively obtained in the course of normal recommendation dialogues and
used to direct future conversations with the same user. We present a novel user
model that influences both item search and the questions asked during a
conversation. We demonstrate the effectiveness of our system in significantly
reducing the time and number of interactions required to find a satisfactory
item, as compared to a control group of users interacting with a non-adaptive
version of the system
Meta-Learning with Adaptive Weighted Loss for Imbalanced Cold-Start Recommendation
Sequential recommenders have made great strides in capturing a user's
preferences. Nevertheless, the cold-start recommendation remains a fundamental
challenge as they typically involve limited user-item interactions for
personalization. Recently, gradient-based meta-learning approaches have emerged
in the sequential recommendation field due to their fast adaptation and
easy-to-integrate abilities. The meta-learning algorithms formulate the
cold-start recommendation as a few-shot learning problem, where each user is
represented as a task to be adapted. While meta-learning algorithms generally
assume that task-wise samples are evenly distributed over classes or values,
user-item interactions in real-world applications do not conform to such a
distribution (e.g., watching favorite videos multiple times, leaving only
positive ratings without any negative ones). Consequently, imbalanced user
feedback, which accounts for the majority of task training data, may dominate
the user adaptation process and prevent meta-learning algorithms from learning
meaningful meta-knowledge for personalized recommendations. To alleviate this
limitation, we propose a novel sequential recommendation framework based on
gradient-based meta-learning that captures the imbalanced rating distribution
of each user and computes adaptive loss for user-specific learning. Our work is
the first to tackle the impact of imbalanced ratings in cold-start sequential
recommendation scenarios. Through extensive experiments conducted on real-world
datasets, we demonstrate the effectiveness of our framework.Comment: Accepted by CIKM 202
LambdaOpt: Learn to Regularize Recommender Models in Finer Levels
Recommendation models mainly deal with categorical variables, such as
user/item ID and attributes. Besides the high-cardinality issue, the
interactions among such categorical variables are usually long-tailed, with the
head made up of highly frequent values and a long tail of rare ones. This
phenomenon results in the data sparsity issue, making it essential to
regularize the models to ensure generalization. The common practice is to
employ grid search to manually tune regularization hyperparameters based on the
validation data. However, it requires non-trivial efforts and large computation
resources to search the whole candidate space; even so, it may not lead to the
optimal choice, for which different parameters should have different
regularization strengths. In this paper, we propose a hyperparameter
optimization method, LambdaOpt, which automatically and adaptively enforces
regularization during training. Specifically, it updates the regularization
coefficients based on the performance of validation data. With LambdaOpt, the
notorious tuning of regularization hyperparameters can be avoided; more
importantly, it allows fine-grained regularization (i.e. each parameter can
have an individualized regularization coefficient), leading to better
generalized models. We show how to employ LambdaOpt on matrix factorization, a
classical model that is representative of a large family of recommender models.
Extensive experiments on two public benchmarks demonstrate the superiority of
our method in boosting the performance of top-K recommendation.Comment: Accepted by KDD 201
A design of a multi-agent recommendation system using ontologies and rule-based reasoning: pandemic context
Learners attend their courses in remote or hybrid systems find it difficult to follow one size fits all courses. These difficulties have increased with the pandemic, lockdown, and the stress they cause. Hence, the role of adaptive systems to recommend personalized learning resources according to the learner's profile. The purpose of this paper is to design a system for recommending learning objects according learner's condition, including his mental state, his COVID-19 history, as well as his social situation and ability to connect to the e-learning system on a regular basis. In this article, we present an architecture of a recommendation system for personalized learning objects based on ontologies and on rule-based reasoning, and we will also describe the inference rules required for the adaptation of the educational content to the needs of the learners, taking into account the learner’s health and mental state, as well as his social situation. The system designed, and validated using the unified modeling language (UML). It additionally allows teachers to have a holistic view of learners’ progress and situations
- …