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ML Academy

Neural networks, deep learning, NLP · insight-1424

Train once with the inputs zeroed to prove the model uses its features

Evidence type
practitioner heuristic
Difficulty
easy
Roles
Data scientist, ML engineer
Industries
cross-industry

Summary: situation, action, reason, boundary

  1. Situation

    A network reaches a decent score, but its loss curve looks similar to what a constant prediction would give.

  2. Action

    Replace all inputs with zeros, keep everything else, and train for the same steps. The real model must beat this input-independent baseline by a margin larger than seed noise; if not, debug the data path.

  3. Reason

    An input-independent run isolates what the model learns from labels and sampling alone, which gives the minimum any feature-based model has to beat.

  4. Boundary

    Any supervised network, as one of the first end-to-end checks.

Symptom or risk

The model may be exploiting only the label distribution, the ordering of rows or an ID, so extra features appear to add nothing and nobody knows why.

Exceptions

Sequence models with positional structure, where the zero baseline may still learn from order.

Trade-offs

One short run.

Pitfalls

Comparing a single run against a single run when seeds differ by more than the margin.

Lessons and concepts

Claims and their sources