clfkit report

model logreg · 10 classes · split sizes {'train': 718, 'calib_fit': 359, 'calib_conf': 360, 'test': 360} · calibration: temperature

0.961test accuracy0.017test ECE0.919APS coverage (target 0.90)1.06APS avg set size

1. Model comparison

Internal 80/20 split of the training rows; sorted by validation log-loss (a proper scoring rule).

(none)

2. Calibration

Each calibrator is fitted on calib_fit and evaluated on test. ECE: binned |accuracy - confidence| (15 bins). NLL and Brier are proper scores (lower is better).

methodaccuracyecenllbriermean_confidence
none0.9610.0320.1610.0680.938
temperature0.9610.0170.1600.0660.954
platt0.9440.0310.9070.0940.969
isotonic0.9420.0461.3340.1020.983

3. Conformal prediction sets

Thresholds from calib_conf (n=360); coverage measured on test. Guarantee: marginal coverage ≥ 0.90 (and ≤ 0.903 for continuous scores) on average over calibration draws, if data are exchangeable. Per-class coverage is not guaranteed by the marginal method; Mondrian conformal fixes this per class at the cost of larger sets.

methodcoverageavg_set_sizesingletonsemptyworst_class_cov
lac0.9000.9110.9110.0890.714
lac_mondrian0.9140.9750.9420.0420.800
aps0.9191.0580.8390.0610.857
aps_mondrian0.9281.1390.7920.0530.857

4. Abstention (selective classification)

Answer only if confidence ≥ 0.8250. On calib_conf: 330 answered, 5 wrong, simultaneous upper bound on selective risk 0.0492 ≤ target 0.05 (Clopper-Pearson, Bonferroni over 53 fixed thresholds, δ=0.05).

On test: coverage 0.914, selective risk 0.0152. AURC 0.0043.

Guaranteed: with prob. ≥ 1-δ over the held-out draw, the true error rate among answered inputs is ≤ target, for future data from the same distribution. Not guaranteed: per-input correctness, the realised rate on a small batch, the fraction answered, or anything under drift.

5. Robustness

Exact L2 certificate for the logistic-regression baseline in its preprocessed features (standardised numerics / one-hot / TF-IDF): no perturbation of norm below the radius can change its predicted label. Clean accuracy 0.961; median certified radius 1.320.

Empirical stability of the final model (logreg) under random noise (numeric: Gaussian with sd = σ × feature sd; text: each token dropped with prob. σ). Random noise is much weaker than adversarial noise: this is a smoke test, not a certificate.

sigmaagreementstable_all
0.0500.9980.994
0.1000.9880.972
0.2000.9810.964
0.5000.9410.869

Generated by clfkit. Raw numbers: summary.json.