ConceptIntermediateAI Opportunity & Model Strategy / When NOT to use AI / #4

What does it mean for a problem to be underspecified, and why does that break AI solutions?

TRACE a definition nobody had written down, tested on Kestrelfeed's appeals tool, Recourse

Kestrelfeed is a photo and video app. Recourse is the tool inside it that reads an appeal, checks it against the policy, and decides whether a takedown should stand or reverse. Xochitl Marrone runs product for the team that built it. This is the quarter she learned that a shrinking backlog and a right answer are not the same thing.

The direct answer
A problem is underspecified when nobody, not the model and not the people judging it, can write down one example input and agree beforehand on the single correct output for it. That is different from hard: a hard problem has a right answer that takes real skill to reach, an underspecified one has no agreed right answer to reach at all. It breaks AI solutions because there is no target left to train, score, or improve against, so a better model just produces a more confident version of the same argument.
Do this, in order
  1. Check whether people can agree on the correct answer before blaming the model.Why: this is the one test the whole diagnosis turns on.
  2. Separate "hard" from "underspecified" out loud, every time.Why: a hard problem has a right answer waiting to be found. An underspecified one does not.
  3. Never let a short instruction like "handle it fairly" stand in as the whole spec.Why: three people can read the same four words and each build a different product.
  4. Name the real cause candidates before picking one: weak model, inconsistent reviewers, or no shared definition.Why: jumping straight to "the model needs more data" wastes a retrain on a problem retraining cannot touch.
  5. Run the retrain-and-recheck test: does the disagreement survive a genuinely better model.Why: this is the one check that proves the problem was never about model quality.
  6. Fix it by writing the missing definition down, not by tuning the model again.Why: a written definition, tested against real cases, is the only thing that gives the model, and the reviewers, a target to hit.

How to answer this, stage by stage

Nobody is grading whether Xochitl can define a word. They are grading whether she can turn "underspecified" from something that sounds like an excuse into a test she can actually run, out loud, under a follow-up.

1
Pin the definition to one real input and output before saying anything abstract
Say it like this
"Let's ground this in one appeal. A video gets taken down, the poster says it shouldn't have been. Underspecified means nobody, including me, could write down in advance the one right call on that exact appeal that everyone in the room would sign off on."
Why this works
A definition tied to a real example survives a follow-up question. A definition made only of abstract words falls apart the moment someone asks "like what?"
2
Say the two-part structure out loud before running either half
Say it like this
"I'll do this in two parts. First, what underspecified actually means, and how it's different from hard. Then, why that specific gap is the thing that breaks an AI solution and not just a hard project."
Why this works
Naming the shape up front stops the answer turning into one long paragraph about "clarity" that never actually defines a thing.
3
Give the working definition, contrasted directly against hard
Say it like this
"A problem is hard when the right answer exists and takes real work to find. It's underspecified when there's no agreed right answer sitting there to find in the first place. Here's the test: give two people the same case, ask them to write down the correct output before either sees the other's answer, and check whether they land on the same thing."
Why this works
This turns a fuzzy word into a check anyone can actually run, instead of a label you reach for after something has already gone wrong.
4
Ground it in a real case before making any claim about why it broke
Say it like this
"Here's a real one. A platform I worked with built an AI tool called Recourse to auto-resolve content appeals it was confident about. The backlog dropped 43 percent in ten weeks. Everyone called it a win. Then a quality audit had three senior reviewers re-judge 240 of the appeals the model had already closed, and they only agreed with each other 61 percent of the time."
Why this works
A real number with a timeframe turns "underspecified problems are risky" from a slogan into something you can picture and check.
5
Name the flattering explanation, then reject it before you're asked to
Say it like this
"The easy read is that the model just wasn't good enough yet. I don't think that's it. Nobody had ever asked the policy team, the creator support team, and legal to write down, before seeing an appeal, what the correct call was. They'd never even been asked whether they agreed with each other."
Why this works
Naming and rejecting the comfortable explanation first shows you're diagnosing the problem, not excusing a rough launch.
6
Run the one check that could have proven you wrong
Say it like this
"Here's the test that actually settles it. They retrained the model. Accuracy against the old historical labels went from 92 to 96 percent, a real improvement. Then they ran a second audit. Reviewer agreement came back at 59 percent, basically the same as before. If this were a model problem, a better model should have closed that gap. It didn't move at all."
Why this works
This is the strongest line in the whole answer, because it's the one check that could have come back the other way and proven the model just needed more training.
7
Close on the real fix, and say the trade-off out loud
Say it like this
"So the fix isn't another retrain. It's making the three teams write down the actual definition of 'handled fairly,' tested against real borderline appeals, before another line of that gets automated. That means pausing auto-resolve on the hard cases for a few weeks, which slows the backlog number back down. I'd take that trade every time, because a confident, well-argued wrong answer nobody agreed to is worse than a slower queue."
Why this works
Ending on a real decision, with the cost named plainly, is what an interviewer remembers once the talking stops.

Let's learn

Kestrelfeed is an app where people post photos and short videos. Recourse is the tool inside it that decides what happens when someone appeals a takedown: it reads the appeal, checks it against the policy the post was flagged under, and either reverses the removal, upholds it, or hands the case to a person.

Hand sketched flow diagram titled What Recourse actually does with one appeal. Four connected steps left to right: appeal arrives, reads policy, confidence score, this step emphasized in a different color, resolves or asks a person.
The confidence score is the quiet step. Everything before and after it is easy to picture. That one is where the judgment actually happens.
Knowledge spark: what is a confidence threshold? The point where a model's own certainty score is high enough that the system acts on its own, without asking a person first. Set it too low and it acts on shaky guesses. Set it too high and a person ends up reviewing almost everything anyway.

Before Recourse could auto-resolve anything, every appeal waited for a person. On a normal week, 12,400 appeals sat in the queue, and the average wait was 11 days. Once Recourse started auto-resolving the appeals it was confident about, at a confidence bar of 0.85, the queue moved fast. By week ten the backlog was down 43 percent, and most appeals got an answer the same day.

Here is the part that matters. The extra speed was never the problem. The problem showed up four weeks later, when a routine quality audit asked three senior reviewers to look at 240 of the appeals Recourse had already closed and decide, on their own, whether the call was right. They agreed with each other only 61 percent of the time.

Recourse hadn't gotten worse. Nobody had ever agreed on what "right" meant in the first place.
Reviewer agreement vs. model accuracy, across three audits
100% 50% 0 91%, after the rubric 96%, flat since retrain Week 14 Week 24 Week 30
Reviewer agreementModel accuracy vs. historical labels
The model got measurably better between week 14 and week 24. Agreement barely moved. It only jumped once the three teams wrote the definition down, at week 30, with no further retraining at all.

Skip past that and keep shipping on the old directive, "resolve appeals fairly," and Recourse quietly becomes a machine that hands out confident, well-argued decisions that a third of the company would have made differently. Nobody notices until an appeal that should have gone one way goes the other, in public, and there is no shared definition anyone can point to that says the tool was wrong.

The choice I would take back We let "resolve appeals fairly" stand as the entire spec. Nobody made the policy team, the creator support team, and legal write down, in advance, what the correct call was on ten real borderline appeals. If we had, we would have found the disagreement in a week, not two quarters.

What I would leave alone: the clear-cut appeals. When a post breaks a rule in an obvious way and the appeal has no real argument in it, all three teams agree almost every time, 95 percent in the same audit. Automating those needs no new definition. The definition problem only lives in the borderline cases.

The lesson: a short instruction sounds specified because it is short, not because it is actually pinned down. Before you build toward one, hand it to two people who care about different things and see if they would point at the same case and give the same answer. If they would not, you do not have a target yet. You have a hope wearing a sentence.

Now here is the same thing as a story

Say the short version above out loud if you get cut off early. Read this one when there is room to actually feel why the backlog number lied.

Xochitl Marrone could read an appeal in under a minute and already know, before she reached the last line, whether it was the kind that never should have been removed or the kind where the poster was hoping nobody would check the rule twice. She had worked trust and safety appeals at Kestrelfeed for four years before Recourse existed. She knew the terrain the way a good waiter knows a menu, without having to think about it.

The directive came down in one line on a slide: resolve appeals fairly, cut the backlog. Nobody in the room argued with it. Why would they. Her team built Recourse to read each appeal, check it against the written policy, and act on its own once it was confident, past a bar of 0.85. It shipped in week six.

For a while, it was the best kind of quiet. Every morning the backlog number was smaller than the day before. By week ten it was down 43 percent, and someone put the chart on a slide in the all-hands. At launch the team had spot-checked a sample of Recourse's calls every single day. After a month of the sample looking clean, that dropped to once a week. By week ten, with the number that good, the daily check had quietly stopped being anyone's actual job. The quarterly audit would catch anything real. That was the plan, on paper.

The audit landed on schedule, unremarkable, the kind of thing that shows up as a line item on a calendar nobody dreads. Three senior reviewers were asked to re-judge 240 appeals Recourse had already closed, blind to what the tool had decided. Xochitl wasn't even in the room. Someone forwarded her the results on a Tuesday afternoon. Agreement across the three reviewers: 61 percent.

Hand sketched timeline titled Two quarters at Kestrelfeed, and the gap that never closed. Five milestones left to right: directive ships, resolve appeals fairly and cut the backlog. Recourse auto-resolves, confidence bar at 0.85, week 6. Backlog drops 43 percent, week 10, called a win. First audit, 61 percent agree, week 14, three reviewers. Second audit, still 59 percent, week 24, after retraining, this last milestone emphasized in a different color.
Five points on the same two quarters. The gap that mattered sits between the fourth mark and the fifth, where retraining changed nothing.

She pulled the raw disagreements herself and read them one by one at her desk after most of the floor had gone home. Her first guess was the model. She checked Recourse's own confidence scores on the disputed appeals; nearly all of them were high, the tool had been sure. Her second guess was the reviewers, maybe the newer ones hadn't caught the latest policy update. She checked that too: no. The disagreement wasn't lopsided toward one reviewer. All three disagreed with each other, in different directions, on different appeals.

Hand sketched comparison diagram titled Three honest guesses for why reviewers keep disagreeing. Three panels: model needs work, not accurate enough yet. Reviewers need training, grading inconsistently. Fair was never defined, confirmed by the test, this panel in a different color.
Two guesses that would have been comfortable to blame, and one that meant the fix was never going to be a retrain.

She could picture the meeting where "resolve appeals fairly" became the entire spec, because she had been in it. Four people, one bullet point on a slide, a nod around the table. Nobody had asked, out loud, what a correct decision on a borderline appeal actually looked like, because everyone in the room already privately knew what they meant by fair. They just did not know they meant three different things.

Hand sketched labeled parts diagram titled Handled fairly, three different ways. Center icon a scale labeled Handled fairly question mark. Three labeled callouts around it: policy, match the rulebook exactly. Support, go easy on clean records. Legal, whatever survives a challenge.
Same appeal, same word, three different answers depending on which team was reading it.

To check it properly, her team pulled 40 real appeals, 20 clear-cut and 20 borderline, and asked the three teams to score each one blind, before anyone saw what Recourse had decided.

Hand sketched decision tree titled Write the correct answer down before you see the model's. Root box, three teams score the same appeal, blind. Two branches: clear-cut appeal, leads to 95 percent agree. Borderline appeal, leads to 34 percent agree.
One test, run twice on two kinds of case, and only one of the two results matched what the audit had already shown.
Reviewer agreement rate, clear-cut vs. borderline appeals
100% 50% 0 95% Clear-cut appeals 34% Borderline appeals
Clear-cut, obvious rule breakBorderline, real argument either way
Ninety-five percent down to thirty-four, on the same test. The average of the two, 61 percent, was exactly what the first audit found, and it hid a case that was fine and a case that was not.

Six weeks later, the same 20 borderline appeals got scored again, this time against a written rubric the three teams had actually agreed on, line by line, sentence by sentence, until they stopped disagreeing. Agreement came back at 91 percent. Recourse itself had not been touched since the last retrain.

The first version asked Recourse to guess at a definition nobody had written down. The second version gave it one.

What she would tell herself, the day they put that 43 percent drop on a slide: a backlog going down is not the same as a question getting answered. They had made the queue quieter. They had not made anyone agree.

TRACE, for telling a hard problem from an undefined one

Not a script for sounding careful about definitions. TRACE is what stops a falling backlog number from being mistaken for a solved question, the moment someone asks why the reviewers still disagree.

TTimeline. Lay out what shipped, including the parts that looked like wins.
The directive shipped first, then Recourse's auto-resolve at a 0.85 confidence bar, then the backlog dropped 43 percent by week ten and got celebrated. The first audit, at week 14, found 61 percent reviewer agreement. Retraining by week 20 raised model accuracy to 96 percent. A second audit at week 24 still showed only 59 percent agreement.
The gap that matters is not between the directive and the audit. It is between week 20 and week 24, where a real model improvement changed nothing about whether people agreed.
RRecut. Slice the number instead of trusting the average.
A 61 percent average agreement rate looked like a moderately shaky tool. Split by case type, it was 95 percent on clear-cut appeals and 34 percent on borderline ones. The average hid a case that was fine and a case that was not close to fine.
A single average is almost never the honest number. Slicing it is what tells you where to actually look.
AAssume nothing. The flattering explanation does not get to stand in for a real one.
"The model just needs to be more accurate" is the explanation that makes everyone look fine, since it points at a machine instead of a decision made in a planning meeting. It is also the explanation a flat agreement rate, measured before and after a real accuracy gain, rules out directly.
The most comfortable explanation is the cheapest one to reach for, and it rarely survives being checked.
CCause candidates. Name the honest options, then test the one that actually fits.
Three real candidates: the model was not accurate enough yet, the reviewers were grading inconsistently, or nobody had ever agreed on what "fair" meant. The real diagnostic check is simple: can two people write down, in advance, the single correct output for the same case. On clear-cut appeals, yes, 95 percent of the time. On borderline ones, no, only 34 percent of the time.
Only the third candidate explains why the gap tracks case type instead of tracking the model or any one reviewer.
EEvidence test. The one check that could have proven the model was still the problem.
Retrain the model, then recheck agreement. If it were a model problem, a real accuracy gain, 92 to 96 percent, should have closed some of the gap. It did not. Agreement stayed at 59 percent. Disagreement that survives a genuinely better model was never something a model could have fixed.
This is the strongest move in the whole framework, because it is the one check that risked coming back the other way and proving the model was still at fault.

One alternative worth naming and rejecting: collecting all that disagreement as more training data and retraining on whichever answer the historical record leaned toward most. That was on the table. It got turned down, because training on the majority view just picks a winner among three real, unresolved positions and hides the argument instead of settling it; the first hard borderline case that leans the other way brings the whole disagreement straight back. The AI-specific risk worth saying plainly: a model trained on inconsistently labeled human decisions will still sound completely sure of itself, because fluent, confident language is not the same thing as a correct or defensible one, so any real fix checks whether the humans who produced the training labels agreed with each other before trusting an accuracy number measured against those labels at all. And the trade-off, accepted on purpose: pausing auto-resolve on the borderline slice for a few weeks, while the actual definition gets written down, costs Kestrelfeed a slower backlog number, and it is worth it, because a confident wrong answer nobody agreed to is a worse cost than a queue that moves a little slower.

And if you want to be sure it really works, try it somewhere else

Same five letters, a hiring tool instead of an appeals tool. The word this time is not "fair." It is "culture fit," and it breaks the same way.

Sorrelwood is a recruiting platform companies use to screen resumes before a person looks at them. Pieternel Aldecott runs people analytics at a firm that uses it. Asked the same question cold, in a fairness review rather than a content appeal, she finds the identical shape under a completely different tool.

Mapped onto TRACE: the timeline is a directive, months earlier, telling the screening tool to flag candidates who were a strong culture fit, shipped and praised for speeding up hiring. Recut is department by department: the flag looked reasonable on average and cratered specifically in two departments with the newest hiring managers. Assume nothing rules out "the model is biased" as the first, most flattering-to-nobody explanation, before it has been checked. Cause candidates line up the same three honest options: the model is biased, hiring managers score inconsistently, or "culture fit" was never actually defined. Evidence test: the hiring manager, the people analytics lead, and a team lead each score 15 borderline resumes blind, before seeing the model's flag. On measurable criteria like required certifications, agreement is 92 percent. On "culture fit," it is 29 percent.

Hand sketched quadrant diagram titled Sorting Sorrelwood's hiring criteria by how well defined they are. X axis how much people agree on the definition, from everyone disagrees to everyone agrees. Y axis how easy it is to check, from subjective to objective. Four points plotted: years of experience and required certification, both high on both axes. Communication style, medium on both axes. Culture fit, low on both axes, bottom left corner.
The criterion furthest from agreed-on is also the one everyone kept treating as if it were obvious.

Swap the trigger and it still runs.
Speed: an interviewer caps you at ninety seconds. Skip straight to the definition and the evidence test; the audit numbers are what you would add back if asked to go deeper.
Cost: there is no scheduled review to point to live. Say what you would check instead: "I would pull ten borderline cases and ask two people who care about different things to score them blind, today, not wait for a quarterly review."
The model got better, for real: say Recourse's accuracy against its old labels jumps to 99 percent. The evidence test still runs exactly the same way. A better model changes how confidently it repeats an answer, not whether that answer was ever agreed on.

Where people run it wrong.
They treat any low agreement number as proof the model is biased or broken, without first checking whether the humans agree with each other.
They fix it by adding more training examples, which only teaches the model to repeat whichever definition happened to win in the data, not the correct one.
They stop at the audit number and never run the blind test, so they are never sure whether they found a real gap or just two tired reviewers on a bad Friday.

How to use it live. The moment someone says a number "looks bad," buy two seconds by asking one question back: would two careful people, working blind, actually agree on the right answer here? That question is the whole method in one breath.

Flashcards (tap any card to flip it)

1 · THE FRAMEWORK
What framework fits telling a hard problem apart from an undefined one?
Tap to flip
ANSWER
TRACE: timeline, recut, assume nothing, cause candidates, evidence test. Used here to diagnose reviewer disagreement over AI appeal decisions, not a metric that fell off a cliff.
2 · THE PEOPLE
Who is this answer about?
Tap to flip
ANSWER
Xochitl Marrone, senior product manager for trust and safety at Kestrelfeed, and the three teams, policy, creator support, and legal, who each read "fair" differently.
3 · THE TIMELINE
When did the real evidence actually show up?
Tap to flip
ANSWER
Backlog dropped 43 percent by week 10. First audit at week 14 found 61 percent reviewer agreement. Retraining by week 20 raised model accuracy to 96 percent, but a second audit at week 24 still showed only 59 percent agreement.
4 · THE CAUSE CANDIDATES
What three honest reasons could explain the disagreement?
Tap to flip
ANSWER
The model was not accurate enough yet. The reviewers were inconsistent. Nobody had ever agreed on what "fair" meant. The evidence points to the third.
5 · THE OLD DECISION
What decision would Xochitl take back?
Tap to flip
ANSWER
Letting "resolve appeals fairly" stand as the entire spec, with nobody asked to write down, in advance, the correct call on real borderline appeals.
6 · THE NUMBER
Fill in the blank: reviewers agreed ___ percent of the time on clear-cut appeals, and only ___ percent on borderline ones.
Tap to flip
ANSWER
95 percent. 34 percent. That gap, not the 61 percent average, is what separates a genuinely hard call from an undefined one.
7 · THE EVIDENCE TEST
What is the one check that actually proves a problem is underspecified, not just hard?
Tap to flip
ANSWER
Retrain the model, then recheck agreement. If accuracy climbs but reviewer agreement stays flat, no amount of model improvement was ever going to fix it.
8 · CROSS-PRODUCT TRANSFER
Section 4 runs this same check on a different product. Which one, and what does it find?
Tap to flip
ANSWER
Sorrelwood, a resume-screening tool. "Culture fit" scores only 29 percent agreement among reviewers, while a measurable criterion like a required certification scores 92 percent, the same shape of gap in a hiring tool instead of an appeals tool.

Check yourself Score: 0 / 0

True or false
1. True or false: once the reviewer agreement rate came back at 61 percent, that alone proves Recourse's model was not accurate enough.
  • True
  • False
Show hint
Look at what the retrain-and-recheck test actually shows.
Show answer
False. A low agreement number tells you people disagree, not who is wrong. The retrain-and-recheck test is what actually separates a model problem from a definition problem, and here it ruled the model out.
Fill in the blank
2. Fill in the blank: after retraining, model accuracy against historical labels rose from ___ percent to ___ percent, but reviewer agreement barely moved, landing at ___ percent.
Show hint
Check the line chart and flashcard 3.
Show answer
92. 96. 59. The model got measurably better. The reviewers' agreement stayed flat.
Multiple choice
3. Which of these is the strongest evidence that Recourse's real problem was an undefined target, not a weak model?
  • A. The backlog dropped 43 percent in ten weeks.
  • B. Reviewer agreement stayed at about 59 to 61 percent both before and after the model got measurably more accurate.
  • C. Three reviewers were asked to re-judge 240 appeals.
  • D. The confidence bar was set at 0.85.
Show hint
Check the evidence test step in the TRACE recap.
Show answer
B. A, C, and D are context, not proof. Only B is a checkable test that could have come back the other way, and it is the one that actually rules the model out.
Short answer, where it wouldn't matter
4. Name one kind of appeal on Kestrelfeed where this exact problem would NOT show up, and say why.
Show hint
Look at "What I would leave alone" in Let's learn.
Show answer
Model answer: Clear-cut appeals, where a post breaks a rule in an obvious way and the appeal has no real argument. All three teams agreed 95 percent of the time on those, because there was nothing left to disagree about.
Short answer, apply it yourself
5. Think of a product you use that runs on an instruction like "flag the good ones" or "find the relevant results." What would the write-down-the-answer-in-advance test actually reveal about it?
Show hint
Check whether two people who use it for different reasons would give the same query the same "correct" answer.
Show answer
Model answer: If two people who care about different things wrote down, before looking, which result counts as correct for the same query, and they gave different answers, that is a sign the tool is aiming at a target that was never actually agreed on, not a tool that simply is not good enough yet.
Short answer, the number question
6. If the second audit's reviewer agreement had come back at 88 percent instead of 59, would the underspecification diagnosis still hold? Why or why not?
Show hint
Think about what the flat number is actually standing in for.
Show answer
Model answer: No, or at least much less strongly. An 88 percent agreement rate after retraining would look like a model that genuinely closed the gap, pointing back toward "the model wasn't accurate enough yet" instead of "nobody agreed on the target." The diagnosis leans hard on that number staying essentially flat.
Before you close the answer
Why this works
Tests whether you can tell a model that is genuinely failing from a target that was never defined, and whether you will keep reaching for another retrain once retraining can no longer move the number.
Follow-up traps
"Isn't 61 percent agreement just proof the reviewers need better training?" Response: the disagreement was not split into consistent camps against one reviewer, it moved with case type, not with any one person, and the three teams disagreed for genuinely different reasons, matching the rulebook versus going easy versus staying defensible, which points at the definition, not at reviewer skill.

"Couldn't you just train the model on whichever definition scores best against the historical data and move on?" Response: training on whichever definition happens to dominate the historical record just picks a winner among three real, still-unresolved views and hides the argument instead of settling it, and it comes back the moment a new case leans the other way.
If pressed
A real build would report how much the human reviewers actually agreed with each other on the training and eval labels themselves, something like a Cohen's kappa score, before trusting any accuracy number measured against those labels at all. A 96 percent accuracy score against labels that only 60 percent of reviewers agree on is not really 96 percent right. It is 96 percent consistent with an argument that was never settled.
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