Worked case · Reference condition · 12 figures

Target and intervention

Choose a target that matches the action

Figure 01 / 12

The evaluated population

The evaluated population — Target and intervention. Count; one closed observation cohort. Exact values are in the figure data below.
Count; one closed observation cohort

The cohort contains 24,600 mature transactions, of which 443 have the defined synthetic outcome: Confirmed unauthorized-payment loss. The outcome is known by construction here. In production, label uncertainty and selection must be recorded separately.

Figure data and text version
OutcomeCount
Confirmed unauthorized-payment loss443
Other labeled outcomes24,157

A model trained to predict disputes does not automatically estimate unauthorized fraud or preventable loss. The label should match the outcome and action being evaluated.

The reference case starts with the stated population and a functioning evidence path. The owner is risk operations.

All amounts, rates, capacity limits, and outcomes in this case are synthetic. The three conditions are separate assumptions for comparison. A better result in the response condition is not measured proof that the proposed control causes that improvement. The figures expose the calculation and its limits; a real deployment needs its own evidence.

Read the result

The rule flags 716 of 24,600 mature transactions. Of those flags, 354 meet the synthetic target, giving 49.44% precision. It misses 89 target events. Under the stated cost assumptions, residual loss and operating friction total $17,579. The important result is the connection between the population, action, capacity, and outcome—not one isolated score.

Model inputs and calculated values

Inputs below are the case-specific values. Each figure states the condition-specific assumptions and units used in its calculation. Calculated values are rounded for display.

InputValue
population24,600
prevalence0.018
severity145
Calculated valueResult
population24,600
positive443
negative24,157
tp354
fp362
fn89
tn23,795
loss12,905
severity145
precision49.44
recall79.91
Figure 02 / 12

Four outcomes of the rule

Four outcomes of the rule — Target and intervention. Counts; rows are actual labels, columns are actions. Exact values are in the figure data below.
Counts; rows are actual labels, columns are actions

The rule flags 354 synthetic positives and 362 negatives. It misses 89 positives. A flagged item is a decision to intervene; it is not proof of fraud, a legal prohibition, or any other real-world conclusion.

Figure data and text version
Known outcomeFlaggedNot flagged
Confirmed unauthorized-payment loss35489
Other outcome36223,795
Figure 03 / 12

Three rates with different denominators

Three rates with different denominators — Target and intervention. Rates within this cohort. Exact values are in the figure data below.
Rates within this cohort

Precision is 49.44%, recall is 79.91%, and the false-positive rate is 1.5%. Changing the denominator changes the meaning. This record keeps each numerator attached to the population from which it came.

Figure data and text version
MetricNumeratorDenominatorResult
Precision35471649.44%
Recall35444379.91%
False-positive rate36224,1571.5%
Figure 04 / 12

Precision changes with prevalence

Precision changes with prevalence — Target and intervention. Percent; fixed conditional detection rates. Exact values are in the figure data below.
Percent; fixed conditional detection rates

This sensitivity plot holds recall at 80% and false-positive rate at 1.5%, then changes prevalence. It is an algebraic comparison, not a forecast. Even unchanged detection quality can produce a very different review queue when the base rate changes. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Assumed prevalencePrecision %
0.1%5.07
0.5%21.14
1%35.01
2%52.12
5%73.73
10%85.56
Figure 05 / 12

The threshold trade-off

The threshold trade-off — Target and intervention. Count in the same cohort. Exact values are in the figure data below.
Count in the same cohort

Six illustrative score bands use a stated pair of detection rates. Lower sensitivity can reduce false alarms but miss more target events. These points do not come from a trained model and do not establish the best operating threshold. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Score bandTrue positivesFalse positives
Band 14343,624
Band 24161,933
Band 3381845
Band 4319290
Band 522297
Band 611124
Figure 06 / 12

A transparent loss-and-friction calculation

A transparent loss-and-friction calculation — Target and intervention. Illustrative USD; expected cost under stated intervention assumptions. Exact values are in the figure data below.
Illustrative USD; expected cost under stated intervention assumptions

At $145 severity per missed synthetic positive, residual loss is $12,905. Review costs $2,864; lost contribution on false alarms is $1,810. The calculation assumes intervention prevents all flagged-positive loss and each false alarm loses the stated contribution. Relax those assumptions before applying it to a real policy.

Figure data and text version
Cost componentUSD
Missed-positive loss12,905
Review cost2,864
False-alarm contribution1,810
Figure 07 / 12

Observed outcomes mature over time

Observed outcomes mature over time — Target and intervention. Count; final outcome fixed. Exact values are in the figure data below.
Count; final outcome fixed

The final synthetic positive count is 443. Earlier observations reveal only a stated fraction. Comparing a day-1 cohort with a day-30 cohort would confuse label age with control quality. This curve models observation delay only; it does not change the final outcome. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Days after eventObserved positives
180
3155
7266
14363
30443
Figure 08 / 12

Review demand and available capacity

Review demand and available capacity — Target and intervention. Items in the cohort window. Exact values are in the figure data below.
Items in the cohort window

The flag count is 716. The comparison capacity is an illustrative 984 reviews per cohort window. A mathematical rule can be coherent while its resulting workload exceeds the operating team’s capacity. Capacity is not permission to ignore an applicable mandatory control.

Figure data and text version
Queue measureItems
Flagged for review716
Available capacity984
Excess demand0
Figure 09 / 12

A feature is an observation with provenance

A feature is an observation with provenance — Target and intervention. Illustrative data contract. Exact values are in the figure data below.
Illustrative data contract

This evidence contract supports choose a target that matches the action. A value needs its event time, arrival time, scope, and source. Keeping unavailable evidence distinct from a measured zero prevents an outage from becoming a falsely reassuring feature.

Figure data and text version
FieldExampleMeaning
entity_refTarget and interventionSubject of this case
event_time2026-09-18T09:00:00ZWhen the event occurred
received_time2026-09-18T09:00:02ZWhen the system learned it
signal_statusavailableEvidence quality, not an outcome
label_definitionConfirmed unauthorized-payment lossThe target used in these calculations
Figure 10 / 12

Missing evidence changes the observed population

Missing evidence changes the observed population — Target and intervention. Count; each row is the same cohort. Exact values are in the figure data below.
Count; each row is the same cohort

The cells show an explicitly constructed completeness profile for three signal groups. The stress condition removes more history and device evidence. Missingness does not prove the target outcome; it changes what the decision process knows.

Figure data and text version
Signal groupAvailableMissing
Identity evidence24,354246
Activity history24,108492
Context signal23,3701,230
Figure 11 / 12

Evidence, score, and action remain separate

Evidence, score, and action remain separate — Target and intervention. Decision lifecycle. Exact values are in the figure data below.
Decision lifecycle

The policy can use choose a target that matches the action only within its approved scope. The action record must retain which evidence was available, which model or rule ran, and which action was actually applied. The final action can differ from the score recommendation when a separate constraint applies.

Figure data and text version
StageRecord
ObserveTarget and intervention: evidence as of the decision time
EvaluateRule flags 716 of 24,600 mature transactions
ApplyRecord action, reason, owner, and expiry
ReconcileJoin the action to later outcomes without overwriting history
Figure 12 / 12

What the result cannot establish

What the result cannot establish — Target and intervention. Interpretation boundary. Exact values are in the figure data below.
Interpretation boundary

Observed classifications do not reveal every counterfactual. The synthetic labels make arithmetic possible, but production decline data is selected by prior policy. Keep measured outcomes, assumed prevention, and unknown alternatives separate when reporting impact.

Figure data and text version
ClaimEvidence in this caseLimit
Detected target354 known synthetic positives flaggedProduction labels may be delayed or wrong
Prevented lossAssumed 51,330 USDRequires an intervention-effect assumption
Customer impact362 synthetic negatives flaggedNot every flag causes abandonment
Unobserved alternativeOutcome without the actionNeeds a valid evaluation design

Connect the result to the system

Define the target, maturity window, exclusions, and intervention assumptions separately.

Check the population, evidence, permitted action, and actual effect together. A balanced calculation can still use the wrong population; a successful response can still leave an unknown financial outcome. The case’s numerical result applies only to its stated assumptions.

Sources and further reading

The chapter sources support the concepts and scope. They do not prescribe the synthetic model rates.

  1. scikit-learn: model evaluation metrics
  2. scikit-learn: probability calibration
  3. Federal Reserve SR 26-2: revised model-risk guidance (2026)