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Data Annotator job description

A Data Annotator is a professional responsible for meticulously analyzing and labeling textual data, aiding in the development of Machine Learning models by providing accurately categorized and annotated information.

Alexandros Pantelakis
Alexandros Pantelakis

HR content specialist at Workable, delivering in-depth, data-driven articles to offer insights into industry and tech trends.

Use this Data Annotator job description template to advertise open roles for your company. Be sure to modify requirements and duties based on the unique needs of the role you’re hiring for.

What is a Data Annotator?

A Data Annotator plays a crucial role in the realm of data science and machine learning. They meticulously examine and categorize large datasets, ensuring that the information is accurately labeled and organized. This role is essential in training and refining machine learning models, as the quality of data annotation directly impacts the effectiveness of these models.

What does a Data Annotator do?

Data Annotators work with extensive textual datasets, labeling and categorizing data for use in Machine Learning and AI algorithms. They are responsible for accurately identifying specific entities in text, such as company names or job titles, classifying documents, and ensuring that the data fed into machine learning models is precise and reliable. They may also be involved in validating model outputs and spotting recurrent patterns in data, contributing to the overall accuracy and efficiency of AI systems.

Data Annotator responsibilities include:

  • Identification and labeling of named entities in text
  • Classifying documents into different categories
  • Validating the output of Machine Learning models
  • Identifying common patterns in datasets

Job brief

We are seeking a meticulous and organized Data Annotator for a 6-month contract, potentially extendable to 1 year.

In this role, you will collaborate with our data science team and play a vital part in handling large textual data sets. Your primary responsibilities will include identifying and labeling named entities in text, classifying documents, validating machine learning model outputs, and identifying patterns in data.

This position offers a chance to contribute significantly to the development of advanced machine learning models and to work on challenging tasks that have a broad impact.


  • Identification and labeling of named entities in text, such as companies, locations, job titles, and skills.
  • Classifying documents into various categories.
  • Validating outputs of Machine Learning models.
  • Identifying common patterns in datasets.
  • Ensuring accuracy and reliability in data annotation.

Requirements and skills

  • A high degree of reliability and attention to detail.
  • Solid organizational skills.
  • Ability to work independently and efficiently.
  • A university degree (or currently studying).
  • Oral and written proficiency in English.
  • Proficiency in other languages, copywriting, or copy-editing experience, experience as a translator, background in linguistics, experience with linguistic annotation, and familiarity with annotation tools and platforms are desirable.
  • Knowledge of ontologies and text markup languages.

Frequently asked questions

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