Classifier audit

The retained model is available only to inspect a failed evaluation. Its output is not a forward return estimate.

server waking, first score can take a minute

CLASSIFIER QUARANTINED A temporal split did not prevent future-history and cancellation-sign leakage
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Review real invoices

Invoice 536365 · real invoice sample

Samples are real invoice lines. The classifier is retained to demonstrate the audit failure, not to guide a return decision.

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    audit-only retained-model score

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    Customer history check

    History check · what this customer has actually done

    Classifier audit record · headline metrics withdrawn
    Classifier status: quarantined, with former ROC-AUC and lift claims withdrawn
    Future-history leakage: customer and category aggregates were built from the full dataset
    Cancellation-sign leakage: negative quantity and line revenue reveal cancellation rows
    Temporal evaluation status: invalid until every fold rebuilds features as of its cutoff
    Excessive returners flagged 294 customers at 5% contamination
    Segmentation silhouette 0.238, k=4
    Recommender Recall@10 0.093, NDCG@10 0.046

    UCI Online Retail II, Dec 2009 to Dec 2011, returns labeled by C-prefixed invoices; 22.8% of rows lack a CustomerID and the pipeline handles them rather than dropping them.

    Why the temporal split was not enough

    The original design used a date split, but the matrix joined customer and category aggregates computed from the full dataset. It also retained sign-coded fields that identify cancellation rows. Once those features contain the future or the outcome itself, a temporal split only moves contaminated rows into different periods.

    Use limits · what the retained score cannot support
    1. This ML demo sleeps after extended inactivity. First wake can take a moment; runs after that are quick.
    2. The number displayed above is an artifact of the retained model. It is not a valid probability or a basis for a customer action.
    3. The legacy API field names remain for compatibility while the classifier stays quarantined.
    4. The customer history and anomaly views are descriptive. The anomaly flag is behavioral, not moral.
    5. The sample button draws from real invoice lines so the leakage failure can be inspected on concrete cases.