Tagging @lvwerra since we haven't really discussed what the inputs and outputs of measurements should be (as opposed to metrics) -- maybe worth discussing, so once we start adding more, they all have a similar format?

Hi @meg-huggingface, thanks a lot for adding the data measurements! This is also connected to #18. A few general remarks about the PR:

Measurement API

Similar to how it is done in #34 I think it would be great if we establish a uniform interface for all measurements. Following metrics we could establish the following:

Metrics

from evaluate import load_metric

metric = load_metric("accuracy")
metric.compute(references=references, predictions=predictions)
>>> {"accuracy": 0.7}

Measurement

from evaluate import load_measure

measure = load_measure("npmi")
measure.compute(data=data)
>>> {"nmpi": 0.88}

A uniform interface will help users familiar with the metrics part of evaluate/datasets easily adapt to measurements.

Classes

It would simplify making the measurements uniform if they built on top of a class to metrics (see here). The above could be easiest achieved by creating a Measurement class that inherits what's currently called Metric. We probably want to refactor this a bit such that:

EvaluationModule #or whatever we want to call this
 |-- Metric
 |-- Comparison
 |-- Measurement

Where EvaluationModule is essentially Metric and then Metric as well as the other subclasses inherit from it.

Template

Once we have the class structure we could add a template for measurements in templates/ and expand the evaluate-cli create command to allow to create a new measurement and push it to the hub.

Miscellanious

• For the README template of measurements we could probably build on @sashavor's template for metrics templates/{{ cookiecutter.metric_slug }}/README.md
• Dependencies: I see that there is e.g. a streamlit dependency - is this necessary?
• it would be good to use the evaluate logger for consistency

cc @lhoestq @douwekiela

Ok with you to close this PR and create smaller PRs like #44 for each measurement with the same structure? Also what do you think @sashavor?

Yes! Perfect :)