Cognitive diagnosis seeks to estimate the cognitive states of students by exploring their logged practice quiz data. It plays a pivotal role in personalized learning guidance within intelligent education systems. In this paper, we focus on an important, practical, yet often underexplored task: domain-level zero-shot cognitive diagnosis (DZCD), which arises due to the absence of student practice logs in newly launched domains. Recent cross-domain diagnostic models have been demonstrated to be a promising strategy for DZCD. These methods primarily focus on how to transfer student states across domains. However, they might inadvertently incorporate non-transferable information into student representations, thereby limiting the efficacy of knowledge transfer. To tackle this, we propose Zero-1-to-3, a domain-level zero-shot cognitive diagnosis framework via one batch of early-bird students towards three diagnostic objectives. Our approach initiates with pre-training a diagnosis model with dual regularizers, which decouples student states into domain-shared and domain-specific parts. The shared cognitive signals can be transferred to the target domain, enriching the cognitive priors for the new domain, which ensures the cognitive state propagation objective. Subsequently, we devise a strategy to generate simulated practice logs for cold-start students through analyzing the behavioral patterns from early-bird students, fulfilling the domain-adaption goal. Consequently, we refine the cognitive states of cold-start students as diagnostic outcomes via virtual data, aligning with the diagnosis-oriented goal. Finally, extensive experiments on six real-world datasets highlight the efficacy of our model for DZCD and its practical application in question recommendation. The code is publicly available at https://github.com/bigdata-ustc/Zero-1-to-3.

Learner modeling is a crucial task in online learning environments, where Cognitive Diagnosis Models (CDMs) are employed to assess learners' knowledge mastery levels based on recorded response logs. However, the prevalence of noise in recorded response data poses significant challenges, including various behaviors such as guess and slip, casual answers, and system-induced errors. The existence of noise degrades the accuracy of diagnosis results and learner performance predictions. In this work, we propose a general framework, Adaptive Response Denoising (AdaRD), designed to salvage CDMs from the influence of noisy learner-exercise responses. AdaRD extends existing CDMs, incorporating primary training for denoised CDMs and auxiliary training for additional denoising support. The primary training employs binary Generalized Cross Entropy (GCE) loss to slow down the large update of learner knowledge states caused by noisy responses. Simultaneously, we utilize the variance of diagnosed knowledge mastery levels between primary and auxiliary diagnosis modules as a criterion to downweight high-variance responses that are likely to be noisy. In this manner, the proposed framework can prune noisy response learning during training, thereby enhancing the accuracy and robustness of CDMs. Extensive experiments on both real-world and synthetic datasets validate AdaRD's effectiveness in mitigating the impact of noisy learner-exercise responses.

Computerized Adaptive Testing (CAT) arises as a promising personalized test mode in online education, targeting at revealing students' latent knowledge state by selecting test items adaptively. The item selection strategy is the core component of CAT, which searches for the best suitable test item based on students' current estimated ability at each test step. However, existing selection strategies behave in a brute-force manner, which results in the time complexity being linear to the number of items (N) in the item pool, i.e., O(N). Thus, in reality, the search latency becomes the bottleneck for CAT with a large-scale item pool. To this end, we propose a Search-Efficient Computerized Adaptive Testing framework (SECAT), which aims at enhancing CAT with an efficient selection strategy. Specifically, SECAT contains two main phases: item pool indexing and item search. In the item pool indexing phase, we apply a student-aware spatial partition method on the item pool to divide the test items into many sub-spaces, considering the adaptability of test items. In the item search phase, we optimize the traditional single-round search strategy with the asymptotic theory and propose a multi-round search strategy that can further improve the time efficiency. Compared with existing strategies, the time complexity of SECAT decreases from O(N) to O(logN). Across two real-world datasets, SECAT achieves over 200x speed up with negligible accuracy degradation.