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Measuring the Partial-Credit Gap: A Strict Benchmark on Vietnam's 2025 Convex Marking Scheme
- Source
- arXiv — Computers and Society
- Published
- Last verified
- 20 Aug 2026
- Confidence
- High
- Evidence
- Original document retained
- Reading time
- 1 min
- Country
- International
- Relevant to
- Finance & Investment, Research & Evidence, Policy & Regulation, Operations & Delivery, Partners & Funders, Technology & Data
Executive summary
What happened, and why should leadership care?
A recent research paper highlights a critical discrepancy in evaluating performance, particularly for language models, when traditional accuracy metrics are applied to assessment schemes that utilize non-additive, convex grading. The 2025 reform of Vietnam's National High School Graduation Examination serves as a case study, demonstrating how a convex grading system for multi-part questions penalizes partial knowledge more severely than standard proportional credit, leading to an underestimation of 'correctness' by conventional metrics. This has implications for how performance is measured and interpreted in contexts with complex scoring.
Why this matters
Why is this strategically important?
This analysis underscores the importance of aligning evaluation methodologies with the specific scoring mechanisms of an assessment, particularly in high-stakes environments. Misalignment can lead to inaccurate performance measurement, potentially misrepresenting capabilities or outcomes, and influencing resource allocation or strategic direction based on flawed data. Organizations need to understand the nuances of grading to ensure fair and accurate assessment, whether for human or automated systems.
Key insights
What should be noted from the evidence?
- Traditional evaluation benchmarks often assume proportional credit for partial knowledge, scoring responses as simply right or wrong.
- Non-additive, convex grading schemes invalidate the assumption that partial knowledge is worth proportional credit.
- Vietnam's 2025 National High School Graduation Examination Part II uses a convex grading scheme for questions with four true/false statements.
- In this scheme, three correct statements out of four earn 0.50 points, not the 0.75 points expected from standard proportional accuracy metrics.
- This difference illustrates a 'partial-credit gap' where partial knowledge is awarded less than proportional credit.
Evidence and confidence
How far can this assessment be trusted?
High confidence. Named institution, original document retained and analysis corroborated.
Analysis is prepared editorially by Aziz Shuaib Ausi. The original publication remains the authoritative record, and executive judgement remains entirely human.
Source
Where does this originate?
Reported by arXiv — Computers and Society · International. This briefing summarises the publication for executive use; the document itself is not reproduced here.
Read the original publication