A Case-Based Solution to the Cold-Start Problem in Group Recommenders

AAAI Conferences

In this paper we offer a potential solution to the cold-start problem in group recommender systems. To do so, we use information about previous group recommendation events and copy ratings from a user who played a similar role in some previous group event. We show that copying in this way, i.e. conditioned on groups, is superior to copying nothing and also superior to copying ratings from the most similar user known to the system.


Differential Neighborhood Selection In Memory-Based Group Recommender Systems

AAAI Conferences

As recommender systems have become commonplace to support individual decision making, a need has also been recognized for systems that tailor and provide recommendations to a group of users together rather than individuals alone. Group recommender research to date has focused on evaluating strategies for aggregating profiles of group members to form a consolidated group profile or for aggregating recommendations to individual group members as a consolidated group recommendation list. This paper presents a novel neighborhood selection approach for group recommendation in the context of a neighborhood-based Collaborative Filtering system. We evaluate the performance of this approach with respect to group characteristics such as size and group member similarity. Results show that this approach can result in more accurate predictions for the group, particularly for groups that are more homogenous.


SAGA: A Submodular Greedy Algorithm For Group Recommendation

arXiv.org Machine Learning

In this paper, we propose a unified framework and an algorithm for the problem of group recommendation where a fixed number of items or alternatives can be recommended to a group of users. The problem of group recommendation arises naturally in many real world contexts, and is closely related to the budgeted social choice problem studied in economics. We frame the group recommendation problem as choosing a subgraph with the largest group consensus score in a completely connected graph defined over the item affinity matrix. We propose a fast greedy algorithm with strong theoretical guarantees, and show that the proposed algorithm compares favorably to the state-of-the-art group recommendation algorithms according to commonly used relevance and coverage performance measures on benchmark dataset.


SAGA: A Submodular Greedy Algorithm for Group Recommendation

AAAI Conferences

In this paper, we propose a unified framework and an algorithm for the problem of group recommendation where a fixed number of items or alternatives can be recommended to a group of users. The problem of group recommendation arises naturally in many real world contexts, and is closely related to the budgeted social choice problem studied in economics. We frame the group recommendation problem as choosing a subgraph with the largest group consensus score in a completely connected graph defined over the item affinity matrix. We propose a fast greedy algorithm with strong theoretical guarantees, and show that the proposed algorithm compares favorably to the state-of-the-art group recommendation algorithms according to commonly used relevance and coverage performance measures on benchmark dataset.


How to Improve Multi-Agent Recommendations Using Data from Social Networks?

AAAI Conferences

User profiles have an important role in multi-agent recommender systems. The information stored in them improves the system's generated recommendations. Multi-agent recommender systems learn from previous recommendations to update users' profiles and improving next recommendations according to the user feedback. However, when the user does not evaluate the recommendations the system may deliver poor recommendations in the future. This paper presents a mechanism that explores user information from social networks to update the user profile and to generate implicit evaluations on behalf of the user. The mechanism was validated with travel packages recommendations and some preliminary results illustrate how user information gathered from social networks may help to improve recommendations in multi-agent recommender systems.