Hybrid Personalization Using Declarative and Procedural Memory Modules of the Cognitive Architecture ACT-R
Kevin Innerebner, Dominik Kowald, Markus Schedl, Elisabeth Lex
TL;DR
The paper addresses the opacity of sub-symbolic recommender systems by proposing a hybrid ACT-R architecture that combines declarative memory and procedural memory via production rules to enable psychology-informed, transparent personalization. It outlines how item interactions are stored as chunks with activations and how production rules adjust activations to drive top-k recommendations, providing explanations grounded in symbolic reasoning. Key contributions include a hybrid retrieval-and-reasoning framework, rule-classification and adaptation mechanisms (individual, group, global), explainability interfaces, and plans to study cognitive biases and counterfactuals. If realized, this approach could yield human-centered recommender systems that reflect cognitive processes and biases, with mechanisms for counterfactual analysis and bias mitigation.
Abstract
Recommender systems often rely on sub-symbolic machine learning approaches that operate as opaque black boxes. These approaches typically fail to account for the cognitive processes that shape user preferences and decision-making. In this vision paper, we propose a hybrid user modeling framework based on the cognitive architecture ACT-R that integrates symbolic and sub-symbolic representations of human memory. Our goal is to combine ACT-R's declarative memory, which is responsible for storing symbolic chunks along sub-symbolic activations, with its procedural memory, which contains symbolic production rules. This integration will help simulate how users retrieve past experiences and apply decision-making strategies. With this approach, we aim to provide more transparent recommendations, enable rule-based explanations, and facilitate the modeling of cognitive biases. We argue that our approach has the potential to inform the design of a new generation of human-centered, psychology-informed recommender systems.
