Lightweight QA and Sampling Notes

~6 min · Updated Sep 2025

Introduction

Annotation projects are rarely perfect. Even with a solid taxonomy, consistency can slip, annotators can disagree, and resources are limited. In large industry projects, whole teams of reviewers handle quality assurance. In smaller, research-driven projects like the Language of Endometriosis Project, that kind of infrastructure is not available.

This article shares the lightweight QA and sampling methods I used to review outputs without big budgets or large teams. These heuristics were not perfect, but they were good enough to train annotators, refine categories, and build prototypes like the pain tagger that feeds into the Explain My Pain app.

Why QA matters

Without QA, annotation quickly becomes unreliable. A patient might describe “a heavy burning in my pelvis,” and if one annotator tags it as quality, another as metaphor, and a third as intensity, the dataset loses coherence. QA ensures categories are applied in the same way, which is crucial if the data is going to support an NLP tool or clinical application.

In the endometriosis corpus, QA turned hundreds of individual descriptions into a dataset that was consistent, reusable, and trustworthy.

Constraints in small projects

Large annotation efforts rely on multiple reviewers, inter-annotator agreement scores, and detailed adjudication workflows. In my project there was:

The heuristics I used

Sampling small but often

I regularly sampled 5–10% of annotations instead of reviewing the whole dataset. This gave me a quick sense of consistency without slowing the workflow.

Checking edge cases

I deliberately pulled out ambiguous or unusual phrases, often metaphorical descriptions from the corpus such as “a monster clawing at me.” These revealed where the taxonomy needed clarification.

Quick agreement checks

When I worked with a collaborator, we double-annotated a small batch of about 50 lines. We did not calculate full statistics, but compared results and discussed disagreements. This gave us feedback without heavy computation.

Rolling refinements

If a category was repeatedly misapplied, I updated the guidelines immediately and noted it. For example, we clarified when something was intensity (“mild cramps”) versus quality (“throbbing pain”).

Sanity scans

Before locking a dataset, I skimmed quickly across annotations, looking for glaring inconsistencies such as categories applied to non-pain words or missing location tags. This worked as a lightweight audit.

Why this worked

The combination of small samples, edge-case focus, and rolling refinement gave me enough confidence to move forward. It did not reach the robustness of large-team QA, but it was fit for purpose.

These heuristics meant I could train the prototype pain tagger on data that was good enough for experimentation. Without them, the tool would have been unreliable.

Lessons for annotators

Closing

Lightweight QA and sampling are about pragmatism: doing what is possible within the limits of a small project without giving up on quality. In the Language of Endometriosis data, these methods kept the taxonomy usable, the annotations consistent, and the path open toward building the pain tagger and the Explain My Pain app.