Time series is the most prevalent form of input data for educational prediction tasks. The vast majority of research using time series data focuses on hand-crafted features, designed by experts for predictive performance and interpretability. However, extracting these features is labor-intensive for humans and computers. In this paper, we propose an approach that utilizes irregular multivariate time series modeling with graph neural networks to achieve comparable or better accuracy with raw time series clickstreams in comparison to hand-crafted features. Furthermore, we extend concept activation vectors for interpretability in raw time series models. We analyze these advances in the education domain, addressing the task of early student performance prediction for downstream targeted interventions and instructional support. Our experimental analysis on 23 MOOCs with millions of combined interactions over six behavioral dimensions show that models designed with our approach can (i) beat state-of-the-art educational time series baselines with no feature extraction and (ii) provide interpretable insights for personalized interventions. Source code: https://github.com/epfl-ml4ed/ripple/.
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在推理时间检测到分布(OOD)数据对于机器学习的许多应用至关重要。我们提出Xood:一个新型的基于极值的OOD检测框架,用于图像分类,由两种算法组成。第一个是Xood-M完全无监督,而第二个Xood-L则是自我监督的。两种算法都依赖于神经网络激活层中数据的极端值捕获的信号,以区分分布和OOD实例。我们通过实验表明,Xood-M和Xood-l均优于效率和准确性的许多基准数据集的最先进的OOD检测方法,从而将虚假阳性率(FPR95)降低了50%,同时改善了推论时间数量级。
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命名实体识别是一项信息提取任务,可作为其他自然语言处理任务的预处理步骤,例如机器翻译,信息检索和问题答案。命名实体识别能够识别专有名称以及开放域文本中的时间和数字表达式。对于诸如阿拉伯语,阿姆哈拉语和希伯来语之类的闪族语言,由于这些语言的结构严重变化,指定的实体识别任务更具挑战性。在本文中,我们提出了一个基于双向长期记忆的Amharic命名实体识别系统,并带有条件随机字段层。我们注释了一种新的Amharic命名实体识别数据集(8,070个句子,具有182,691个令牌),并将合成少数群体过度采样技术应用于我们的数据集,以减轻不平衡的分类问题。我们命名的实体识别系统的F_1得分为93%,这是Amharic命名实体识别的新最新结果。
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