labeler

A labeler is a term with two common meanings. In manufacturing and packaging contexts, a labeler refers to a device or person that attaches or assigns identification labels to products, containers, or packaging. In data science and machine learning contexts, a labeler describes the person or software that assigns descriptive labels to data items to create labeled datasets for training algorithms.

In industry, labeling machines, sometimes called label applicators or wrap-around labelers, apply adhesive labels to items as they move along a conveyor. They may print labels on demand, format text, and position labels on bottles, cartons, or cases with high speed and precision. Systems can be passive, reading existing information to determine label content, or active, driven by upstream data such as inventory or order details. Quality considerations include label placement, readability, durability, and adherence under varying handling or environmental conditions.

In data labeling for AI, a labeler annotates items such as images, text, audio, or video with category names, attributes, or other metadata. The process is often performed by human annotators using labeling tools and may be organized via crowdsourcing or dedicated teams. Key elements include a defined labeling taxonomy, clear task instructions, and quality control measures such as review and inter-annotator agreement. Labeled data enable supervised learning, model evaluation, and downstream tasks such as object detection, sentiment analysis, or transcription. Ethical considerations include privacy, bias, and the need for transparent data provenance and consistent annotation guidelines.