@inproceedings{wu-etal-2026-tailoring,
    title = "Tailoring Diagnostic Modeling to Individual Learners: Personalized Distractor Generation via {MCTS}-Guided Reasoning Reconstruction",
    author = "Wu, Tao  and
      Chen, Jingyuan  and
      Lin, Wang  and
      Zhan, Jian  and
      Li, Mengze  and
      Jin, Fangzhou  and
      Zhang, Min  and
      Kuang, Kun  and
      Wu, Fei",
    editor = "Liakata, Maria  and
      Moreira, Viviane P.  and
      Zhang, Jiajun  and
      Jurgens, David",
    booktitle = "Proceedings of the 64th Annual Meeting of the {A}ssociation for {C}omputational {L}inguistics (Volume 1: Long Papers)",
    month = jul,
    year = "2026",
    address = "San Diego, California, United States",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/ingest-acl/2026.acl-long.983/",
    pages = "21500--21524",
    ISBN = "979-8-89176-390-6",
    abstract = "Distractors{---}incorrect yet plausible answer choices in multiple-choice questions (MCQs){---}are vital in educational assessments, as they help identify student misconceptions by presenting potential reasoning errors. Current distractor generation methods typically produce shared distractors for all students, ignoring the individual variations in reasoning, which limits their diagnostic effectiveness. To tackle this challenge, we introduce the task of Personalized Distractor Generation, which tailors distractors to each student{'}s specific cognitive flaws, inferred from their past question-answering (QA) history. While promising, this task is particularly demanding due to the limited number of QA records available for each student, which are insufficient for training, as well as the absence of their underlying reasoning process. To overcome this, we propose a novel, training-free two-stage framework. In the first stage, Monte Carlo Tree Search (MCTS) is used to reconstruct the student{'}s reasoning process from past errors, creating a student-specific misconception prototype. In the second stage, this prototype guides the simulation of the student{'}s reasoning on new questions, generating personalized distractors that resonate with their individual misconceptions. Our experiments, conducted on 1,361 students across 6 subjects, demonstrate that this approach outperforms existing methods in generating plausible, personalized distractors, and also effectively adapts to group-level settings, highlighting its robustness and versatility."
}