Moderation is the quality assurance process of checking, adjusting, and calibrating marking across different raters, markers, sites, or institutions to ensure fairness and consistency. Where rater training prepares examiners before assessment, moderation monitors and corrects after or during the marking process.
The fundamental question moderation answers: Would this candidate receive the same score regardless of who marked their work?
Scores from different raters or groups are adjusted statistically to compensate for systematic differences:
Statistical moderation preserves the rank order of candidates within each group but adjusts levels to a common standard. It requires sufficient data; small sample sizes make statistical adjustment unreliable.
Raters meet to review and discuss sample scripts/performances together. They:
This is the most common form in institutional contexts and closely resembles standardisation meetings used in rater training.
A senior examiner or team leader reviews a sample of marked work to verify that the rater has applied the rating scale correctly. If systematic issues are found (e.g., a rater consistently ignoring one criterion), the rater receives feedback and may have their marks adjusted.
| Context | Moderation approach |
|---|---|
| IELTS Writing | Double-marking for a proportion of scripts; statistical monitoring of each examiner's patterns |
| Cambridge exams | Team leader reviews sample of each examiner's marking; statistical post-hoc analysis |
| University departmental essays | Social moderation meetings; blind second-marking of borderline scripts |
| Language school end-of-course tests | Team discussion of anchor scripts; spot-checking across markers |
The terms are sometimes used interchangeably, but a useful distinction is:
Both are needed. Standardisation without moderation assumes training was perfectly effective. Moderation without standardisation has nothing to moderate against.
Without moderation: