How Does Data Labeling Work?

数据标签是如何工作的?

2021-03-29 23:25 TAUS

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Data labeling is a key factor in artificial intelligence (AI) which enables a machine learning model to learn and output accurate predictions. In order for any supervised machine learning model to output accurate results, it relies on two things: an abundant amount of data and accurate labels. Data labeling is the process of assigning a group of raw data a label and it is an important aspect in the data pre-processing stage of any machine learning problem and occurs during. Labeled data can be defined as a group of data points that are assigned a target data point, or label. An example of this can be seen in the popular Iris Data Set. This dataset describes 3 types of iris plants ( labels). The descriptive data points, or features, are sepal length, sepal width, petal length, and petal width. The output class, or label, is the type of iris plant. Thus, the labels give value to the dataset which would otherwise have little practical meaning. Why is Data Labeling Important? An AI model performs best when the quality of the training data is high. One major aspect that defines high-quality input data is accurate labels, making data labeling a crucial step in executing an AI model. Any machine learning model will perform better when it has learned from accurate labels in the training set. Unlabeled data exists in many forms around us: your photos, emails, videos, satellite imagery, food labels, etc. Although this data provides a good base when seeking any sort of intelligence, it is missing labels. Labeled data is valuable because it can reflect our real-world conditions and provide us insight into decision-making. With labeled data, we can predict important conditions in the present or future, such as stock market trends, financial forecasting and, weather patterns., etc. To make informed business decisions, it is important for any organization to have accurate labels in its predictive modeling. Measuring the accuracy of a machine learning model includes a direct comparison of the predicted labels versus the true labels. Therefore accurate labels yield an enterprise not only better predictions, but also improve a product, analytics, market insights, business decisions, and can help a business scale. Methods of Data Labeling Data labeling tasks often include data annotation, tagging, classification, and transcription, among others. Companies today often use a variety of techniques or services to label their data. These include the following: Internal processes rely on employees within an organization to complete data labeling tasks. Oftentimes data annotators are specifically hired for this purpose. The downfall of this method is that this can consume company resources and be time-consuming to set up. Outsourcing involves hiring third-party temporary or freelance contractors. This is a good option if an organization does not wish to allocate internal resources to such labeling tasks. Crowdsourcing can be ideal when internal resources are not sufficient for data labeling purposes. It involves collaborating with third-party data partners who can offer workers and technical guidance in setting up and/or deploying a machine learning model. This is an attractive option for companies that do not have an adequate data science team. Automated processes are when a machine will label datasets for you, entirely skipping the need for human labeling tasks. This machine learning automated approach can be useful for large-scale data labeling tasks that could be either too expensive or tedious to be executed through manual labor. Quality Assurance Quality assurance (QA) practices are often integrated with the data labeling process. Even though it isthough is highly useful in the long run, this procedure frequently gets overlooked. Quality assurance checks help ensure that labels are being made appropriately and any errors are flagged. It provides another level of confidence in your dataset and model predictions on a larger scale. These checks are important in both manual and automated labeling techniques alike. One way to place a quality assurance check is to regularly conduct audits for data labeling tasks, which can consist of a start-to-finish examination of the data labeling process. Data Labeling in Machine Learning Diving deeper into the methods of data labeling for machine learning outlined above, we can categorize these tasks into two main buckets: manual data labeling and automated data labeling. Manual Data Labeling Data labeling that occurs internally is usually executed manually. Generally, the team performing the task has domain knowledge in order to provide more accurate labels. Because these tasks are looked over by humans, the quality of the labels is controlled and tuned according to business or modeling needs. The downside, however, is that manual data labeling can be incredibly time-consuming and labor-intensive. Furthermore, it is more difficult to scale any AI model in this manner. As the volume of data increases, it becomes overwhelmingly impractical to continue with manual labeling tasks. However, with the emergence of advanced platforms, such as the TAUS HLP Platform, designed to accommodate a large variety of audio/image/text-based data collection and labeling or annotation tasks, and through careful recruitment and management of a qualified global network, custom, fit-to-purpose outputs can be generated. Automated Data Labeling Techniques In automated data labeling techniques, either supervised or semi-supervised learning are used as a sub-task during the preprocessing stage of an AI model framework. This happens during the training dataset preparation step in a larger model architecture. Supervised learning is the process of learning labeled data points and semi-supervised learning combines both labeled and unlabeled data to classify the labels of big datasets. Transfer learning is a technique (often used in deep learning) where a model is trained for executing one task then repurposed for a different but similar task. In our case, a pre-trained model will be used for a labeling task. This initial model would have been exposed to a similar dataset and tuned appropriately. For example, if we wish to learn labels for images of different bird species in the Amazon, we use an initial labeled (and usually smaller) dataset to pre-train our learning model. Once we learn this initial model, we transfer it to our larger unlabeled dataset to perform label predictions, as seen in the figure below. Additional human-approved datasets can be fed into the labeling model to continuously improve labeling predictions. The advantage of transfer learning for data labeling is that it is fast and efficient when we are working with big datasets. The downfall is that there is room for error and the initial pre-trained model will likely perform better than the learned model. Other common automated data labeling techniques and applications include computer vision and natural language processing (NLP). In computer vision, in order to generate a training set, a bounding box consisting of labeled pixels enclosing an image is needed beforehand. Images can be either classified by content or quality type. This data can then be applied to a computer vision model that detects, segments, or categorizes images. In natural language processing (NLP), data labeling entails tagging texts with labels beforehand. NLP classification tasks can consist of identifying text in images, sentiment, files, sounds, etc. Once these labels are generated, they can be incorporated into a training set which can then be used to either repeat the same task or be fed into a different task. Data Labeling Review The quality of data labels in the input data directly translates to the output of a supervised machine learning model. The more accurate the labels, the more accurate the end predictions. Data labeling is a pre-processing step for a larger learning model. Data labeling can be performed by either human evaluation tasks or automated labeling methods. In either scenario, data quality assurance checks are important in evaluating the accuracy of data labels. Valid data labels trickle through an organization’s data structure and provide value to the business.
数据标注是人工智能(AI)中的一个关键因素,它使机器学习模型能够学习并输出准确的预测。 机器监控状态下的学习模型是否输出准确的结果,取决于两个方面:数据量是否丰富,数据标注是否准确。数据标注是给一组原始数据分配一个标签的过程,它是所有机器学习中数据预处理阶段的一个重要方面,发生在数据处理过程中。数据标注可以定义为, 一组数据点分配给目标数据点或标签的过程。 此类例子在虹膜数据集中很常见。本数据集描述了3种鸢尾属植物(标签)。描述的数据点,或特征,是萼片长度,萼片宽度,花瓣长度和花瓣宽度。输出类或标签是虹膜植物的类型。因此,标签赋予数据集价值,否则这些价值几乎没有实际意义。 数据标注为何如此重要? 当训练数据的质量较高时,人工智能模型的性能最佳。 决定输入数据质量的一个主要方面就是数据标签的准确性,这使得数据标签成为执行AI模型的关键步骤。任何机器学习模型,经过训练集中的精确标签学习后,它的表现都会更好。 无标签数据以多种形式存在于我们身边:你的照片,电子邮件,视频,卫星图像,食品标签等等。尽管这些数据在寻求某种情报时提供了很好的依据,但它却是缺少标签的。有标签的数据之所以有价值,是因为它能反映我们现实世界的状况,并为我们的决策提供洞察。有了标签数据,我们就可以预测当前或未来的重要情况,如股票市场趋势,金融预测和天气状况等。 为了做出全面的业务决策,任何组织在其预测建模中具有准确的标签都是重要的。测量机器学习模型精确度的指标包括预测标签与真实标签之间的直接比较。因此,准确的标签不仅能让企业做出更好的预测,还能改善产品,作出分析,获得市场洞察力,进行商业决策,并能帮助企业扩大规模。 数据标注方法 数据标记任务通常包括数据注释,标记,分类和转录等。今天的公司经常使用各种技术或服务来标记他们的数据。这些措施包括: 内部处理靠组织内的员工来完成数据标注。通常,会专门采用数据标注器做此项工作。这种方法的缺点是,这会消耗公司资源,而且设置起来很费时。 外包涉及临时雇用第三方或自由职业承包商。如果一个组织不希望将内部资源用于此类数据标注任务,这会是一个很好的选择。 当内部资源不足以用于数据标签目的时,众包可能是理想的方法。它涉及与第三方数据合作伙伴协作,这些合作伙伴可以为工人在建立和/或部署机器学习模型方面提供技术指导。对于数据团队不够充足的公司来说,这是一个有吸引力的选择。 自动化过程是指机器将为您标记数据集,完全不需要人工标记任务。这种机器学习的自动化方法对于大规模的数据标注任务非常有用,因为这些任务可能成本太高操作繁琐,无法通过人工来执行。 质量保证 质量保证(QA)实践通常与数据标签过程并行完成。尽管从长远来看它是非常有用的,但是这个过程经常被忽视。质量保证检查有助于确保标注合理,并检查出任何的标记错误。它为您的数据集和更大规模的模型预测提升可信度。这些检查在手动标注和自动标注中都很重要。进行质量保证检查的一种方法是定期对数据标签任务进行审计,包括对数据标注过程进行从头到尾的检查。 机器学习中的数据标注 深入研究上面概述的机器学习的数据标注方法,我们可以将这些任务分为两大类:手动数据标注和自动数据标注。 手动数据标记 内部发生的数据标记通常是手动执行的。通常,执行任务的团队拥有领域专业知识,以便提供更准确的标签。因为这些任务是由人来检查的,所以标签的质量是根据业务或建模的需要来控制和调整的。 然而,其缺点是手动数据标记非常耗时耗力。此外,以这种方式衡量任何AI模型都更加困难。随着数据量的增加,继续手动标记任务变得非常不切实际。 然而,随着平台的不断改进,如TAUS HLP平台,这些平台的设计初衷就是为了囊括各种基于音频/图像/文本的数据收集和标签或注释任务,通过细心征聘以及对合格的全球网络、客户进行管理,产出与目的相符的结果。 自动数据标记技术 在自动数据标注技术中,不论完全监控或半监控学习,都算作人工智能模型框架预处理阶段的子任务。这通常在较大模型体系结构中的训练数据集准备步骤期间进行。监控学习是学习标记数据点的过程,半监督学习结合标记数据和未标记数据对大数据集的标记进行分类。 迁移学习是一种技术(经常用于深度学习),在这种技术中,训练模型先执行一个任务,然后重新对模型进行设计来执行一个相似的任务。在我们的例子中,一个预先训练好的模型将用于一个标注任务。这个初始模型将暴露于一个类似的数据集中,然后进行适当的调优。例如,如果我们希望学习亚马逊不同鸟类物种图像的标签,我们使用一个初始标记(通常更小)的数据集来预先训练我们的学习模型。一旦我们学习了这个初始模型,我们就把它转移到我们更大的未标记数据集中,以执行标签预测,如下图所示。 认为通过的数据集会反馈到标记模型中,以持续改进标记预测。迁移学习用于数据标注的优势在于当我们处理大数据集时,它非常快速高效。其缺点是会产生错误,并且初始的预训练模型可能会比学习的模型表现得更好。 其他常见的自动化数据标注技术和应用有计算机视觉和自然语言处理(NLP)。在计算机视觉中,为了生成一个训练集,需要事先生成一个由标记像素组成的包围盒对图像进行包围。图像既可以按内容分类,也可以按质量类型分类。然后可以将这些数据应用于检测,分割或分类图像的计算机视觉模型。 在自然语言处理(NPL)中,数据标注需要用标签对文本进行预先标注。NLP分类任务可以包括识别图像,情感,文件,声音以及其他文本。这些标签一旦生成,它们就会合并到数据训练集中,然后该训练集 再次用于重复任务或者输入到不同的任务中。 数据标记审查 输入数据中数据标签的质量直接通过监控机器学习模型输出反映。标签越准确,最终预测就越准确。数据标注是更大的学习模型的预处理步骤。数据标注既可以通过人为执行,也可以通过自动标注方法来执行。在这两种情况下,数据质量检查在评估数据标签的准确性方面很重要 。有效的数据标签通过组织的数据结构传输,并为业务提供价值。

以上中文文本为机器翻译,存在不同程度偏差和错误,请理解并参考英文原文阅读。

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