PsyDI: Towards a Personalized and Progressively In-depth Chatbot for Psychological Measurements

In the field of psychology, the static nature and lack of customization of psychological test scales, along with the challenge of quantifying psychological indicators, have long been critical issues. Despite numerous attempts to use AI to address psychological challenges, a dynamically interactive psychological test has yet to emerge. In contrast to traditional psychological assessment methods, we propose PsyDI, a multi-modal, interactive, and customized chatbot for psychological assessments, using the Myers-Briggs Type Indicator (MBTI) as an example. PsyDI initiates with user-related multi-modal information, then engaging in customized interaction to discern the user's MBTI type based on their multiple rounds of responses. Despite these advancements, accurately quantifying absolute value of psychological indicators remains challenging. To tackle such difficulty, we introduce the PsyDI framework that trains LLMs to discern the relative magnitude of psychological traits rather than their absolute values. Through various experiments, we demonstrate the effectiveness of the training techniques proposed in PsyDI on various datasets, and we have also launched its web version, reaching about ~3k accesses. Additionally, comprehensive post-deployment data analysis has provided profound insights into the implications and applications of PsyDI, demonstrating its potential to serve as a general framework for psychological assessment.

LightZero: A Unified Benchmark for Monte Carlo Tree Search in General Sequential Decision Scenarios

Building agents based on tree-search planning capabilities with learned models has achieved remarkable success in classic decision-making problems, such as Go and Atari. However, it has been deemed challenging or even infeasible to extend Monte Carlo Tree Search (MCTS) based algorithms to diverse real-world applications, especially when these environments involve complex action spaces and significant simulation costs, or inherent stochasticity. In this work, we introduce LightZero, the first unified benchmark for deploying MCTS/MuZero in general sequential decision scenarios. Specificially, we summarize the most critical challenges in designing a general MCTS-style decision-making solver, then decompose the tightly-coupled algorithm and system design of tree-search RL methods into distinct sub-modules. By incorporating more appropriate exploration and optimization strategies, we can significantly enhance these sub-modules and construct powerful LightZero agents to tackle tasks across a wide range of domains, such as board games, Atari, MuJoCo, MiniGrid and GoBigger. Detailed benchmark results reveal the significant potential of such methods in building scalable and efficient decision intelligence. The code is available as part of OpenDILab at https://github.com/opendilab/LightZero.

FastCover: An Unsupervised Learning Framework for Multi-Hop Influence Maximization in Social Networks

Finding influential users in social networks is a fundamental problem with many possible useful applications. Viewing the social network as a graph, the influence of a set of users can be measured by the number of neighbors located within a given number of hops in the network, where each hop marks a step of influence diffusion. In this paper, we reduce the problem of IM to a budget-constrained d-hop dominating set problem (kdDSP). We propose a unified machine learning (ML) framework, FastCover, to solve kdDSP by learning an efficient greedy strategy in an unsupervised way. As one critical component of the framework, we devise a novel graph neural network (GNN) architecture, graph reversed attention network (GRAT), that captures the diffusion process among neighbors. Unlike most heuristic algorithms and concurrent ML frameworks for combinatorial optimization problems, FastCover determines the entire seed set from the nodes' scores computed with only one forward propagation of the GNN and has a time complexity quasi-linear in the graph size. Experiments on synthetic graphs and real-world social networks demonstrate that FastCover finds solutions with better or comparable quality rendered by the concurrent algorithms while achieving a speedup of over 1000x.