The expansion of large-scale online education platforms has yielded vast amounts of student interaction data for knowledge tracing (KT). KT models estimate students’ concept mastery from interaction data, but the models’ performance is sensitive to input data quality. Gaming behaviors, such as excessive hint use, may misrepresent students’ knowledge and undermine model reliability. However, systematic investigations of how different types of gaming behaviors affect KT remain scarce, and existing studies rely on costly manual analysis that does not capture behavioral diversity. In this study, we conceptualize gaming behaviors as a form of data poisoning, defined as the deliberate submission of incorrect or misleading interaction data to corrupt a model’s learning process. We design Data Poisoning Attacks (DPA) to simulate diverse gaming patterns and systematically evaluate their impact on KT model performance. Moreover, drawing on advances in DPA detection, we explore unsupervised approaches to enhance the generalizability of gaming behavior detection. We find that KT models performance tend to decrease especially for random guess behaviors. Our findings provide insights into the vulnerabilities of KT models and highlight the potential of adversarial methods for improving the robustness of learning analytics systems.

Learning analytics (LA) holds a promise to transform education by utilizing data for evidence-based decision-making. Yet, its application in early childhood education (ECE) remains relatively under-explored. ECE plays a crucial role in fostering fundamental numeracy and literacy skills. While standardized tests was intended to be used to monitor student progress, they have been increasingly assumed summative and high-stake due to the substantial impact. The pressures in succeeding in such standardized tests have been well-documented to negatively affect both students and teachers. Attempting to ease such stress and better support students and teachers, the current study delved into the LA potential for predicting standardized test performance using formative assessments. Beyond predictive accuracy, the study addressed ethical considerations related to fairness to uncover potential risks associated with LA adoption. Our findings revealed a promising opportunity to empower teachers and schools with more time and room to help students better prepared based on predictions obtained earlier before standardized tests. Notably, bias can be significantly observed in predictions for students with disabilities even they have same actual competence compared to students without disabilities. In addition, we noticed that inclusion of demographic attribute had no significant impact on the predictive accuracy, and not necessarily exacerbate the overall predictive bias, but may significantly affect the predictions received by certain demographic subgroups (e.g., students with different types of disability).

Machine Learning (ML) techniques have been increasingly adopted to support various activities in education, including being applied in important contexts such as college admission and scholarship allocation. In addition to being accurate, the application of these techniques has to be fair, i.e., displaying no discrimination towards any group of stakeholders in education (mainly students and instructors) based on their protective attributes (e.g., gender and age). The past few years have witnessed an explosion of attention given to the predictive bias of ML techniques in education. Though certain endeavors have been made to detect and alleviate predictive bias in learning analytics, it is still hard for newcomers to penetrate. To address this, we systematically reviewed existing studies on predictive bias in education, and a total of 49 peer-reviewed empirical papers published after 2010 were included in this study. In particular, these papers were reviewed and summarized from the following three perspectives: (i) protective attributes, (ii) fairness measures and their applications in various educational tasks, and (iii) strategies for enhancing predictive fairness. These findings were summarized into recommendations to guide future endeavors in this strand of research, e.g., collecting and sharing more quality data containing protective attributes, developing fairness-enhancing approaches which do not require the explicit use of protective attributes, validating the effectiveness of fairness-enhancing on students and instructors in real-world settings.

Recommendation methods based on deep learning frameworks have drastically increased over recent years, covering virtually all the sub-topics in recommender systems. Among these topics, one-class collaborative filtering (OCCF) as a fundamental problem has been studied most extensively. However, most of existing deep learning-based OCCF methods are essentially focused on either defining new prediction rules by replacing conventional shallow and linear inner products with a variety of neural architectures, or learning more expressive user and item factors with neural networks, which may still suffer from the inferior recommendation performance due to the underlying preference assumptions typically defined on single items. In this paper, we propose to address the limitation and justify the capacity of deep learning-based recommendation methods by adapting the setwise preference to the underlying assumption during the model learning process. Specifically, we propose a new setwise preference assumption under the neural recommendation frameworks and devise a general solution named DeepSet, which aims to enhance the learning abilities of neural collaborative filtering methods by activating the setwise preference at different neural layers, namely 1) the feature input layer, 2) the feature output layer, and 3) the prediction layer. Extensive experiments on four commonly used datasets show that our solution can effectively boost the performance of existing deep learning based methods without introducing any new model parameters.

With the explosive growth of web resources, an increasingly important task in recommender systems is to provide high-quality personalized services by learning users’ preferences from historically observed information. As an effective preference learning technology, collaborative filtering has been widely extended to model the one-class or implicit feedback data, which is known as one-class collaborative filtering (OCCF). For a long time, pairwise ranking-oriented learning scheme has been viewed as a superior solution than the pointwise scheme for OCCF due to its higher accuracy in most cases. However, we argue that with appropriate model design, pointwise preference learning can achieve comparable or even better performance than the counterpart, i.e., pairwise preference learning. In particular, we propose a new preference assumption, i.e., pointwise preference on user/item-set. Based on this new assumption, we develop a novel, simple, and flexible solution called collaborative filtering via pointwise preference learning on user/item-set (CoFi-points). Furthermore, we derive two specific algorithms of CoFi-points with respect to the involved user-set and item-set, i.e., CoFi-points(u) and CoFi-points(i), referring to preference assumptions defined on user-set and item-set, respectively. Finally, we conduct extensive empirical studies on four real-world datasets with the state-of-the-art methods, and find that our solution can achieve very promising performance with respect to several ranking-oriented evaluation metrics.

Recommender systems play an important role in providing personalized services for users in the context of information overload. Generally, users’ feedback toward items often contain the most significant information reflecting their preferences, which enables accurate personalized recommendation. In real applications, users’ feedback are usually heterogeneous (rather than homogeneous) such as purchases and examinations in e-commerce, which reflects users’ preferences in different degrees. Effective modeling of such heterogeneous one-class feedback is challenging compared with that of homogeneous feedback of ratings. As a response, heterogeneous one-class collaborative filtering (HOCCF) is proposed, which often converts the heterogeneous feedback into two parts (i.e., target feedback and auxiliary feedback), aiming to care more about the target feedback (e.g., purchases ) with the assistance of the auxiliary feedback (e.g., examinations ). In this survey, we provide an overview of the representative HOCCF methods from the perspective of factorization-based methods, transfer learning-based methods, and deep learning-based methods. First, we review the factorization-based methods according to different strategies. Second, we describe the transfer learning-based methods with different knowledge sharing manners. Third, we discuss the deep learning-based methods according to the neural architectures. Moreover, we include some important example applications, describe the empirical studies, and discuss some promising future directions.

Exploiting temporal effect has empirically been recognized as a promising way to improve recommendation performance in recent years. In real-world applications, one-class data in the form of (user, item, timestamp) are usually more accessible and abundant than numerical ratings. In this article, we focus on exploiting such one-class data in order to provide personalized next-item recommendation services. Specifically, we base our work on the framework of time-aware item-based collaborative filtering and propose a simple yet effective similarity measurement called bidirectional item similarity (BIS) that is able to capture sequential patterns even from noisy data. Furthermore, we extend BIS via some factorization techniques and obtain an adaptive version, i.e., adaptive BIS (ABIS), in order to better fit the behavioral data. We also design a compound weighting function that leverages the complementarity between two well-known time-aware weighting functions. With the proposed similarity measurements and weighting function, we obtain two novel collaborative filtering methods that are able to achieve significantly better performance than the state-of-the-art methods, showcasing their effectiveness for next-item recommendation.

In this paper, we propose a novel preference assumption for modeling users' one-class feedback such as "thumb up" in an important recommendation problem called one-class collaborative filtering (OCCF). Specifically, we address a fundamental limitation of a recent symmetric pairwise preference assumption and propose a novel and first asymmetric one, which is able to make the preferences of different users more comparable. With the proposed asymmetric pairwise preference assumption, we further design a novel recommendation algorithm called asymmetric Bayesian personalized ranking (ABPR). Extensive empirical studies on two large and public datasets show that our ABPR performs significantly better than several state-of-the-art recommendation methods with either pointwise preference assumption or pairwise preference assumption.