<p>Summary statistics by funder.</p>

In contrast, expert reviews, defined as assessments conducted by reviewers selected for subject-matter expertise rather than general panel membership, and certain research areas showed modestly higher disagreement. Application amount, reviewer age composition, and temporal trends exhibited limited influence. Only a small share of disagreement stemmed from stable reviewer tendencies (3.1 percent), whereas most variability arose at the application level (24.1 percent) and the residual level (55.2 percent), indicating that disagreement is largely application-specific rather than reviewer-driven.

Inter-rater reliability was moderate across funders: average ICCs ranged from 0.50 to 0.65. Our findings only partly support previous research and indicate that disagreement is driven primarily by application-specific ambiguity and inherent variability in human judgment rather than systematic reviewer characteristics or program features. Consequently, interventions targeting reviewer behaviour alone are unlikely to substantially improve reliability; gains are more likely to come from clearer criteria, more structured review formats, and reducing application-level ambiguity, though such measures are expected to yield only incremental improvements.</p></div>