JU Hongzheng , TANG Jianhang , ZHANG Yang , JING Kebing
Accepted: 2026-03-30
In recent years, an increasing number of studies have focused on modeling users’ multiple interests from their behavioral sequences in order to better capture complex user preferences. However, in implicit modeling scenarios where external auxiliary information such as item categories is unavailable, existing multi-interest models often struggle to accurately determine the interest attribution of individual behaviors. As a result, items that are weakly related or even irrelevant to the target interest are easily aggregated into the same interest representation, leading to the introduction of interest-specific noise. To address this issue, we propose a two-stage denoising multi-interest recommendation algorithm, termed DMIRec, which suppresses interest-specific noise at both the item-feature level and the interest-representation level. In the item denoising stage, learnable adaptive filters are employed to filter out irrelevant item features within each interest, yielding denoised behavior sequences for different interests. In the interest denoising stage, a conditional diffusion model is introduced, where items highly related to the current interest serve as guidance signals to iteratively remove noise components from the corresponding interest representations. Furthermore, to enhance the overall denoising effectiveness, we design a target-guided multi-interest loss that explicitly incorporates the recommendation target into the multi-interest learning process. This loss encourages appropriate responsibility assignment among different interests and reduces the influence of interest-specific noise from an optimization perspective. Experiments conducted on three real-world datasets, Book, Beauty, and Retail Rocket, show that, compared with the best Top-50 recommendation results among baseline models, the proposed method achieves improvements of 8.84%, 2.03%, and 2.27% in Recall; 9.78%, 0.95%, and 0.72% in Hit Rate (HR); and 9.07%, 3.87%, and 2.49% in Normalized Discounted Cumulative Gain (NDCG), respectively. These results demonstrate the effectiveness and robustness of the proposed approach.