Strengths and weaknesses

Understand model confidence through strength and uncertainty.
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Strengths and weaknesses, or SAW, describe confidence-related behaviour in an Umnai model.

SAW provides two measures: strength and uncertainty. Together, they help explain where the model is supported by strong evidence and where its behaviour may be less certain.

Strength

Strength reflects how strong the model is in the activated partitions.

It is based on:

FactorDescription
Training data supportThe amount of training data in each activated partition.
Partition model fitThe quality of the partition’s polynomial model, or then_expression, fit.

A stronger partition is one where the model has more support from training data and a better local fit.

Uncertainty

Uncertainty reflects how certain the model is about its prediction behaviour.

It is based on:

FactorDescription
Estimator varianceVariation across estimators.
Partition prediction varianceVariation in the predictions produced by the partition’s polynomial model.

Higher uncertainty indicates that the model behaviour is less stable or less certain for the activated partitions.

Aggregation

Strength and uncertainty can be aggregated across activated partitions.

This allows SAW to produce confidence estimates at different levels:

LevelDescription
Data segmentConfidence estimate for a selected segment of data.
Batch of predictionsConfidence estimate across a batch of prediction requests.
DatasetConfidence estimate across the dataset as a whole.

At a global level, these aggregations help identify where the model is generally strong, where it is uncertain, and which areas may deserve further review.