Evaluating Model Output Against a Labeled Evaluation Set
A high completeness score only shows that required fields are present; it does not show that the values are correct.
A Good-Looking First Result
Imagine a team reviewing the first results of an automated inspection reporting model. The model turns the audio recording of an inspector into a structured record, and the first numbers look encouraging: nearly every required field is filled in. It is tempting to read that result as a sign the model is ready. This article examines why that conclusion is premature, and how a team in an aerospace quality setting found a remedy that made the record trustworthy enough to pass an audit.
What do you think happens?
If every required field in an inspection record is filled in, is the record accurate and ready for audit?
Reveal answer
Not necessarily, because presence of a field does not show that its value is correct.
Completeness only checks whether required fields are present. The belief that a complete report is a good report is intuitive, but the source shows it can fail: the first model run was nearly complete yet inaccurate.
The belief at the center of this article is intuitive: if every field in a report is present, the report is good. Completeness feels like a proxy for quality. Pause and reason about it before reading on. The rest of the article traces what the team measured, what went wrong, and what they changed.
Three Criteria, Three Questions
The team evaluated the model against a rubric with three criteria. The evaluation set was forty real inspections, each labeled by the customer's quality manager. The labels give the team a reference point: for each inspection, they know what the correct record should contain, so they can check the model's output against it.
The three criteria ask different questions. Structural completeness asks whether the required fields are present at all. Factual accuracy asks whether the values in those fields match what the inspection actually contains. Audit-readiness asks whether the finished record is trustworthy enough to pass an audit. Because these questions are different, a model can do well on one criterion and poorly on another.
- Structural completeness: every required field is present in the record
- Factual accuracy: the values in those fields are correct for the inspection
- Audit-readiness: the finished record can be trusted enough to pass an audit
What the First Run Revealed
The first run cleared the completeness criterion at ninety-six percent, which means the model was usually filling in the required fields. It missed the accuracy criterion at eighty-one percent. Read together, the two numbers show the gap: the record looked finished far more often than it was correct.
The quality manager traced the gap to a specific behavior. The model was inferring fields the inspector had not said aloud. The quality manager flagged this as a serious risk, because an inferred value can look like a legitimate entry while having no basis in the inspection itself.
Reading one inferred entry against the labeled set
A hypothetical inspection is labeled by the quality manager. The inspector mentions a scratch on a panel but says nothing about where on the panel it is. The model writes a location anyway. Is that entry accurate?
- 1Check presence
The location field is filled in, so the completeness criterion sees a passing field.
- 2Check origin
The inspector never said the location aloud, so the value was inferred rather than taken from the inspection.
- 3Check against the label
The labeled record has no basis for the location, so the entry does not match the inspection and fails the accuracy criterion.
The field passes completeness but fails accuracy. Because the entry looks legitimate, a reviewer reading only the finished report would have no easy way to see that it was guessed.
Why a Present Field Hides Its Origin
The lesson is that a field being present says nothing about where its value came from. A reviewer reading the finished report cannot easily tell a value that was spoken from one that was guessed. This is exactly why the failure mattered for audit purposes: an audit asks whether the record can be trusted, and a record that mixes spoken and guessed values cannot be verified from its contents alone.
Constraining the Model to Spoken Fields
The remedy was explicit and simple to state. The model could only fill fields the inspector had spoken. Any field the inspector did not address had to remain missing, and it had to be flagged so that the inspector could complete it manually. The model was no longer allowed to fill gaps with its own inference.
The effect on the scores was a trade-off, and the source reports both sides of it. The constraint reduced the completeness score, since fields the model would previously have guessed now stayed empty. At the same time, it raised the audit-readiness score to one hundred percent. The customer signed the validation milestone after this result.
Mistakes When Reading Evaluation Scores
Common mistake Treating a high completeness score as proof the record is correct
What it looks likeA run reports ninety-six percent completeness and the team declares the model ready.
Why it failsCompleteness only checks that required fields are present. The source's first run was ninety-six percent complete but only eighty-one percent accurate.
Do this insteadReport completeness, accuracy, and audit-readiness separately, and read each one against its own question.
Common mistake Assuming a filled field was taken from the inspection
What it looks likeThe location of a scratch is filled in, so the reviewer assumes the inspector said it.
Why it failsThe model was inferring fields the inspector had not said aloud, and an inferred value can look identical to a spoken one.
Do this insteadCheck whether the value has a basis in the inspection, not just whether the field is present.
Common mistake Judging the constraint only by the completeness drop
What it looks likeCompleteness fell after the change, so the change is treated as a regression.
Why it failsThe constraint was adopted to improve audit-readiness, which rose to one hundred percent. The lower completeness is the cost of that goal, not an accident.
Common mistake Using one criterion to stand in for the other two
Practice: Judging a Record
A team runs a model on a new evaluation set. Completeness is ninety-four percent, accuracy is seventy-nine percent, and the quality manager notes that some fields were filled with values the inspector never mentioned. Explain which criterion is failing, what the model is doing that causes it, and which change in the model's permitted behavior the team should consider, including what that change would cost.
Hints
- Ask which criterion measures presence and which measures whether values match the inspection.
- The source's remedy restricted the model to fields the speaker actually mentioned.
- Think about what happens to the completeness score when unspoken fields stay empty.
Key Takeaways
- A high completeness score only shows that required fields are present; it does not show that the values are correct. The first model run reached ninety-six percent completeness but only eighty-one percent accuracy.
- The three criteria ask different questions: structural completeness asks whether required fields are present, factual accuracy asks whether values match the inspection, and audit-readiness asks whether the record can pass an audit.
- The failure came from the model inferring fields the inspector had not said aloud. A present field gives no sign of whether its value was spoken or guessed.
- Constraining the model to fill only spoken fields and flagging the rest for manual completion lowered completeness but raised audit-readiness to one hundred percent, which is why the customer signed the validation milestone.