# Clarus Stability Score (CSS)

The Clarus benchmark uses a unified score to compare model performance.

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# CSS Definition

CSS is defined as the mean F1 score across all datasets.

CSS = mean(F1_i)

where F1_i is the F1 score for dataset i.

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# Transfer Stability Score (TSS)

To evaluate reasoning transfer:

TSS = mean(F1_transfer)

Where F1_transfer measures performance when the training dataset differs from the testing dataset.

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# Interpretation

High CSS indicates strong performance across regimes.

High TSS indicates the model has learned **stability reasoning rather than dataset-specific patterns**.