Preserve the evidence chain from eligible cases to the release decision
Bind model, data, prompts, scoring, raw outcomes, uncertainty, and approvals into immutable evaluation records that can be checked and rescored without rewriting history.
On this page
The question for today
What you’ll understand
- Specify the immutable identities needed to interpret an evaluation run.
- Separate byte identity, evidence completeness, and semantic validity.
- Audit a scoring revision while preserving eligible denominators and prior reports.
A release report says the assistant passed, but its dataset is a mutable directory named latest, its judge is a provider alias, and the scoring script has changed. The number can no longer be connected reliably to the system that produced it. Evaluation artifacts should preserve that chain before a deployment decision is made. Record immutable inputs, raw outcomes, scoring and inference versions, exclusions, and the final gate result. Reproduction, rescoring, and audit are related tasks, but each asks a different question about the evidence.
Bind a run to concrete inputs and procedures
An evaluation manifest should identify model weights or the strongest available provider revision, tokenizer, system and task prompts, retrieval snapshot, tool configuration, decoding parameters, and resource limits. Include dataset bytes or immutable object identities, inclusion queries, slice definitions, source-group mapping, and rubric version. Record software and scorer versions, seeds or generator states where relevant, hardware and numeric settings, and the supported limits of determinism. A seed does not promise identical outputs across arbitrary kernels, provider changes, or model revisions.
Preserve generated responses, tool results, raw judgments, parse outcomes, per-case scores, and eligibility or exclusion reasons under appropriate access restrictions. Pinned LM Evaluation Harness v0.4.9 documents model and task configuration plus sample logging; those options are building blocks rather than a complete guarantee for every custom evaluation path. Check what your runner actually records. If a remote provider cannot supply immutable model identity or determinism, record that limitation honestly and timestamp the run instead of inventing a reproducibility guarantee.
Use immutable identity without confusing it with validity
A digest binds a recorded identifier to bytes under a specified algorithm and verification process. It does not prove that the labels are correct, the sample is representative, or the system meets its release requirements. Hash the actual artifacts or a documented canonical representation and retain the referenced content. RFC 8785 defines one constrained JSON canonicalization scheme; arbitrary serializer output and semantic equivalence are not automatically the same bytes. Mutable labels can point to immutable releases, but the report must record the resolved identity used for that run.
Create a required-evidence inventory and verify the referenced objects, schemas, signatures where used, and cross-links. Check that per-case outcomes reconcile with aggregates, that every eligible record has its declared disposition, and that the uncertainty procedure used the intended grouping. Evidence completeness is only one audit dimension. A fully present but contaminated test or invalid statistic is still invalid. Conversely, a missing raw-output artifact may prevent rescoring even when the original aggregate was computed correctly. Record what is verified, unavailable, or only attested by another service.
Append corrections and make the decision reproducible
A scoring bug or rubric update should create a new versioned result linked to the preserved original. State which outputs were rescored, which data and model identities stayed fixed, and how eligibility or labels changed. Recompute the affected metrics, uncertainty, and release gates rather than only edit the headline number. If the fix was chosen after inspecting a confirmatory set, disclose that adaptation and determine whether independent confirmation is needed. Preserve failed runs and negative findings so an auditor can understand selection rather than see only the winning report.
The probability lab illustrates a hypothetical completeness requirement without auditing files. Reset, set both p=0.9 and n=10, predict the all-ten-success bar, then inspect. It is 0.9^10≈0.34868 if ten required items are independently available with the same stipulated probability. Real artifacts can share a storage failure and are not verified by this assumption. The display has no manifest, hashing, access control, or semantic validation. Its narrow lesson is that high per-item availability does not imply high all-item availability; actual evidence must be retained and checked against the concrete inventory.
Work it through
Rescore preserved outputs without shrinking away failures
A fictional run has one hundred eligible outputs and originally reports eighty-four passes. A reviewed extraction correction invalidates five of those passes, leaving all other dispositions unchanged. Its fixed audit inventory requires twelve evidence items, of which nine have been verified.
Under the revised declared scoring policy, the pass count is 84−5=79. Keep the eligible denominator 100, so the corrected score is 79%, not 79/95.
The evidence checklist fraction is 9/12=0.75, with three required items still unverified. That fraction does not identify which missing items are most consequential.
Publish a linked scoring-version revision with preserved outputs and both reports, recompute affected uncertainty and gates, and state the incomplete audit. Do not overwrite the original result or describe the whole evaluation as independently reproducible solely from this checklist.
The corrected statistic is 79% and the verified-evidence checklist is 75% complete. Semantic validity and release approval require the actual missing-item, scoring, sampling, and gate evidence.
The living notebook
Explore the model
Interactive lab · probability
A complete evidence chain is a conjunction of required items
Reset, set both p=0.9 and n=10, predict, then inspect the all-ten-success bar: 0.9^10≈0.34868. This is an independent equal-probability availability toy model. It performs no file checks, digest verification, semantic validation, or evaluation audit.
- Mean · np
- 5
- Variance · np(1−p)
- 2.5
- Total probability
- 1
These are exact binomial probabilities for independent trials with one fixed success probability. Playback tours the distribution; it does not resample outcomes. Parameter changes pause playback and recompute the model at the current elapsed time. Reset restores both parameters and returns time to zero. Playback starts paused. Adjust either parameter, then choose Play or Step.
Look forRetain and verify the actual required artifacts. A per-item availability assumption or matching digest cannot establish a valid, complete evaluation claim.
Pause & reason
Check your understanding
Your turn
Try it yourself
A preserved eighty-output run originally has sixty passes. A revised declared parser changes four of those passes to failures without changing eligibility. What score should the linked revision report, and why is deleting the four outputs inappropriate?
Take a moment to make a prediction or work it out on paper. Open a hint when you need one.
Give me a hint
Keep the eligible population fixed while revising its outcome dispositions.
Compare with the solution
The new score is (60−4)/80=56/80=70%. Reporting 56/76 would discard the affected failures and change the denominator. Preserve both scorer versions and raw outputs, document the correction, and recompute any dependent uncertainty or release decision.
Keep the idea
Take it with you
- Bind results to immutable inputs, raw outcomes, scoring rules, and decision procedures.
- Byte identity, checklist completeness, and semantic validity are separate audit dimensions.
- Append corrections with provenance and recompute affected claims without erasing failed evidence.
Read further
Original sources and deeper explanations to follow at your own pace.
Optional progress, saved in this browser when available. Revisit any lesson at any time.
Lesson not marked complete.