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Measuring learner cognition based on their problem-solving performance is a joint discipline of cognitive psychology and machine learning. In the case of learner problem-solving, the interaction between learner and knowledge forms a typical type of signed interaction graph. Interaction graphs are a widely used and effective solution to model the relationships between interacting entities. However, most of previous interaction graph methods are inclined to the observed interactions as positive links but they often fail to consider unobserved and negative links, which leads to an insufficiency in capturing the complete cognition/mis-cognition proximity information. To address this limitation, we propose a knowledge graph representation learning method that is based on signed knowledge interaction network (SKIN). We explicitly model the correct/incorrect cognitive performance as the positively + /negatively − signed links in the graph. The model simultaneously measures the nodes' local and global proximity , and then preserves them in the learned knowledge embedding. We architect a pairwise neural network that is based on a tri-sampling strategy and a sign-driven distance measuring objective function. The network generates knowledge representations by maximizing the knowledge distance between oppositely-signed pairs and minimizing the distance between identically-signed pairs. Our experimental results show the learned knowledge embedding demonstrates a desired Euclidean property and can be visualized with clear classification boundaries. We also show it can power downstream tasks such as learner-performance-prediction. The learned embeddings generate promising prediction scores on this task when compared to several methods in network sign prediction and learner-performance-prediction. [ABSTRACT FROM AUTHOR]

Map-matching is a process that aligns location points on a digital map and it is an essential step in location-based services. However, regular map-matching methods cannot archive very high accuracy due to the errors in raw location data and the complexity of road networks. Hence, the final resort for map matching is often through manual annotation, which is human labour intensive. Therefore, we propose iMatching , an interactive system for map-matching which greatly reduces annotation cost and achieves a high accuracy through an active learning approach. Specifically, we model the mapping of a sequence of location points to a road network as a hidden Markov model and automatically generate an initial result. Then, we select error-prone points on the trajectory and guide the annotator to review, and possibly correct, the results. Our evaluation on both real-world and synthetic data demonstrates that iMatching has a better performance comparing with the existing methods. [ABSTRACT FROM AUTHOR]

Autonomous learning diagnostics, where the students' strengths and weaknesses are disclosed from their observed performance data, is a challenging task in e-learning systems. Current student knowledge models can alleviate some of the problems in learning (i.e. predicting student performance) but they neglect learning diagnostics, which is based on causal reasoning. To this end, we propose a novel heterogeneous attention interpreter with a maximum entropy regularizer on top of a student knowledge model to achieve explainable learning diagnostics. Our model segregates the impact of the homogeneous knowledge points, while promoting the heterogeneous relatives by maximizing their chance to contribute to the prediction. We also propose a multi-spatial knowledge representation that is readily generalizable to other data-driven educational tasks. Extensive experiments on real-world datasets reveal that the proposed method is able to enhance the model's explanatory power, hence increases the trustworthiness towards learning diagnostics. It also brings notable improvement in accuracy in the student performance prediction task. The findings in this paper are adoptable to various types of e-learning systems to assist teachers to gain insights into student learning states and diagnose learning problems. • Autonomously diagnosing learning problems in e-learning systems can be challenging due to the lack of teacher resources (teachers) in e-learning. This work proposes to tackle the explainable learning diagnostics problem using attention-based explanation mechanisms by performing target-source relation prediction. The findings are adoptable to various types of e-learning systems to gain insights into their learner states and diagnose their learning problems. • This paper identifies the importance to use the 'close relatives of knowledge to generate prediction decisions in a knowledge tracing model. We propose a Heterogeneous Attention Relative Detector and a Maximum Entropy Regularizer to detect those relatives, i.e. knowledge relation discovery. • We propose a multi-spatial representation of knowledge in expressing knowledge relations in finer-granularity and low-dimensionality, which can be readily generalized to other data-driven educational tasks. • We provide a different perspective on knowledge graph completion and/or construction. In this perspective, we exploit the interaction data to uncover inner knowledge relations (links) where there is no existing relation data to learn. Our method is effective in settings where the knowledge space is relatively small while the interaction space is very large. [ABSTRACT FROM AUTHOR]