47th European Conference on Information Retrieval - ECIR 2025, Lucca (Italy). 06-10 April 2025
Summary:
Neighborhood-based approaches remain widely used techniques in collaborative filtering recommender systems due to their versatility, simplicity, and efficiency. Traditionally, these algorithms consider similarity functions to measure how close user or item interactions are. However, their focus on capturing similar tastes often overlooks divergent preferences that could enhance recommendations. In this paper, we explore alternative methods to incorporate such information to improve beyond-accuracy performance in this type of recommenders.
We define three mechanisms based on various modeling assumptions to integrate differing preferences into traditional nearest neighbors algorithms.
Our comparison on four well-known and different datasets shows that our proposed approach can enhance the novelty and diversity of the recommendations while maintaining ranking accuracy. Our implementation is available at https://github.com/pablosanchezp/kNNDissimilarities .
Spanish layman's summary:
Este trabajo muestra que incluir preferencias disimilares en recomendadores de vecinos mejora la novedad y diversidad sin perder precisión. Se proponen tres mecanismos evaluados en cuatro conjuntos de datos, con mejoras en métricas más allá de la precisión.
English layman's summary:
This paper explores how incorporating dissimilar preferences into neighborhood-based recommenders improves novelty and diversity without harming accuracy. Three mechanisms are proposed and tested on four datasets, showing better beyond-accuracy performance.
Keywords: Nearest neighbors · Beyond-accuracy evaluation · Dissimilarity
DOI: 
https://doi.org/10.1007/978-3-031-88717-8_14
Published in Advances in Information Retrieval, pp: 187-196, ISBN: 978-3-031-88716-1
Publication date: 2025-04-03.
Citation:
P. Sánchez, J. Sanz-Cruzado, A. Bellogín, Improving Novelty and Diversity of Nearest-Neighbors Recommendation by Exploiting Dissimilarities, 47th European Conference on Information Retrieval - ECIR 2025, Lucca (Italy). 06-10 April 2025. In: Advances in Information Retrieval: 47th European Conference on Information Retrieval, ECIR 2025, Lucca, Italy, April 6–10, 2025, Proceedings, Part IV, ISBN: 978-3-031-88716-1
