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arXiv 1812.02497cs.LGstat.ML
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基于统计杠杆得分的主动学习方法

Active Learning Methods based on Statistical Leverage Scores

Bilkent University(比尔肯特大学);Sabanci University(萨班哲大学)

Cem Orhan, Oznur Tastan

摘要:

在许多现实世界的机器学习应用中,未标记的数据是丰富的,而类标签是昂贵和稀缺的。主动学习器的目标是通过有效地选择有用的示例进行标记,以尽可能少的标记实例获得高精度的模型。我们提出了一个新的选择标准,这是基于统计杠杆分数,并提出了两个新的主动学习方法基于这个标准:ALEVS查询单个例子在每次迭代和DBALEVS查询一批的例子。为了评估池中示例的代表性,ALEVS和DBALEVS使用对每个类的示例计算的核矩阵的统计杠杆分数。此外,DBALEVS通过最大化使用统计杠杆分数和在示例池上计算的核矩阵定义的子模块集函数来选择具有高度代表性但与已经标记的示例不同的一组示例。集合评分函数的子模块属性使我们能够以有效的方式识别具有近似于最优批次的恒定因子的批次。我们在不同数据集上的实验表明,基于杠杆分数的查询是主动学习的一种强大策略。

英文摘要:

In many real-world machine learning applications, unlabeled data are abundant whereas class labels are expensive and scarce. An active learner aims to obtain a model of high accuracy with as few labeled instances as possible by effectively selecting useful examples for labeling. We propose a new selection criterion that is based on statistical leverage scores and present two novel active learning methods based on this criterion: ALEVS for querying single example at each iteration and DBALEVS for querying a batch of examples. To assess the representativeness of the examples in the pool, ALEVS and DBALEVS use the statistical leverage scores of the kernel matrices computed on the examples of each class. Additionally, DBALEVS selects a diverse a set of examples that are highly representative but are dissimilar to already labeled examples through maximizing a submodular set function defined with the statistical leverage scores and the kernel matrix computed on the pool of the examples. The submodularity property of the set scoring function let us identify batches with a constant factor approximate to the optimal batch in an efficient manner. Our experiments on diverse datasets show that querying based on leverage scores is a powerful strategy for active learning.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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