ActiveTigger

An open source collaborative text annotation software for computational social sciences

É. Schultz, J. Boelaert, A. Morin, A. Claesson, E. Bonutti D’Agostini, A. Chatelain, É. Ollion

CREST – Groupe ENSAE-ENSAI – Institut Polytechnique de Paris – CSS@IPP · JADT 2026, Palermo

ActiveTigger = a new tool

  • Why a new tool for text annotation ?
  • Some elements of its general philosophy !
  • … and a demo rather a long discourse

Why a new tool ?

  • Initially, a recurring need: put labels on large text corpora
    • Traing classifiers usually needs specific programming skills…
  • Small LLM (BERT) can be useful once fine-tuned, especially to scale
    • And with embeddings possibility to train classic ML
  • Need for reproducible and on-premises solutions
    • Sensitive data, GDPR, reproducibility, …

Introducing ActiveTigger

An open source tool to collaboratively annotate text corpora and train classifiers with active learning to speed up annotation.

Prototype ~2020 from research practices (J. Boelaert & É. Ollion) \(\rightarrow\) refacto & public v1.0.0 released in May 2026

  • Document-level annotation of large corpora of short texts
  • Sensible defaults first, customization later – avoid overwhelming non-experts
  • End-to-end integration in a single platform
    • Some thoughts on the UX

What are the main use cases ?

  • Annotate quickly a large corpus – fine-tune models from the interface, use active learning to accelerate
  • Collaboratively stabilize a codebook – multiple users + inter-annotator agreement
  • Identify and retrieve documents of interest – BERTopic, regex filters, projections
  • Teach NLP – hands-on experience of a full supervised pipeline, no code required

A growing community

Available code & docs

  • Code: github.com/activetigger/activetigger
  • Docs: activetigger.com/documentation · Discord community
  • Videos are on their way

Demo

How prominent is gender-related research in French social science publications?

Connect

https://demo.activetigger.com

account : jadt{0-50} (same password)

More information

Main features (1): annotate & represent

  • Projects: CSV / Parquet / XLSX import, stratified train/validation/test split, shared across users
  • Annotation: multiclass & multilabel schemes, integrated codebook, history, filters (label, user, regex, prediction), comments
  • Text representations: sentence-transformers embeddings, fastText, DFM, regex features
  • Exploration: tabular view, 2D projections (UMAP / t-SNE), BERTopic topic models

Main features (2): train, evaluate, predict

  • Selection strategies: random, sequential, and active learning (max entropy, target-label probability…)
  • Two families of classifiers:
    • Quick models: scikit-learn classifiers on features, cross-validated, trained in seconds
    • BERT models: Hugging Face fine-tuning, key hyperparameters exposed, loss curves
  • Evaluation: precision / recall / F1 per class, macro F1, confusion matrices, misclassified examples – computed separately on train / validation / test
  • Inference & export: predict on the full dataset or external files; export annotations, features, models, predictions
  • (Experimental) generative panel: prompt external LLM APIs, compare with human annotations

Does it hold up? Validation

Reproducibility – fine-tuning benchmark on a published stance-detection dataset (Luo et al. 2021, global warming, 3 labels):

  • Original BERT-base baseline: accuracy 71% [0.64–0.77]
  • ActiveTigger, same parameters: accuracy 0.69–0.72, within the reported confidence interval
  • The dataset ships with ActiveTigger so anyone can reproduce

Robustness – stress tests on a fresh cloud GPU server (13 min install):

  • 10 simultaneous projects with BERT trainings: queue handled correctly, delay < 0.8s
  • 10 users annotating the same project: all operations OK, delay < 0.4s

Limitations & roadmap

Current limitations for an instance

  • Single-GPU deployments, a few dozen users
  • Exports don’t yet capture full project state

Roadmap

  • Task management refactoring \(\rightarrow\) multi-GPU, larger communities
  • Stable evaluation framework (reference datasets, versioned benchmarks)
  • Generative panel co-designed with the social science community
  • Full project archiving for re-executable annotation campaigns

Takeaways

  • ActiveTigger = end-to-end, collaborative, open source annotation platform for social sciences
  • Encodes supervised-learning best practices in the interface
  • Active learning as the bridge between human annotation and automation
  • Validated, in production, and driven by a research community

Try it: request an account or deploy your own instance - emilien.schultz@ensae.fr