Stacking Outperforms in Debiased Neural Collaborative Filtering: A Comparative Study of IPS-Weighted NCF and Tree-Based Models for Exposure-Biased CTR Prediction

Abstract

Recent developments in recommender systems have increasingly employed deep learning methodologies to confront long-standing challenges, including the modeling of intricate user–item interactions, the incorporation of temporal dynamics, and the mitigation of exposure bias. This study reviews and extends insights from four representative approaches. First, the Convolutional Transformer Neural Collaborative Filtering (CTNCF) model combines convolutional neural networks with Transformer architectures to capture both localized and long-range dependencies within user–item representations, thereby surpassing the performance of conventional Neural Collaborative Filtering (NCF). Second, the Neural Tensor Factorization (NTF) framework advances classical tensor factorization by embedding recurrent and multilayer neural components, enabling the representation of time-varying preferences and nonlinear interactions among latent factors. Third, the Deep Interest Network (DIN) introduces a local activation mechanism that adaptively models user interests in click-through rate prediction, effectively overcoming the limitations of fixed-length embeddings in capturing heterogeneous behavioral patterns; notably, this model has been deployed at scale in industrial advertising contexts. Finally, recent work addressing de-exposure bias in NCF incorporates reward signals derived from the LinUCB algorithm into the neural recommendation process, thereby enhancing both fairness and predictive accuracy by increasing the visibility of underexposed items. Taken together, these contributions illustrate the progression of neural recommender systems from static factorization paradigms toward dynamic, adaptive, and fairness-oriented frameworks, offering both theoretical contributions and practical value for the design of large-scale recommendation platforms.