Paper I: A Funder-Driven Registered Report Initiative Compared with Standard Applications: A Study on Research Quality

Background and aim: A registered report (RR) commits researchers to a peer-reviewed protocol before results are known, reducing reporting bias and promoting open science. Foundation Dam, a health research funder, launched a two-year initiative incentivising RR applications. This study describes projects choosing RR versus standard applications (SA) and assesses differences in reviewer scores.Method: The sample comprises all research grant applicants at Foundation Dam, 2023 to 2025 (N=1194). Using a multilevel linear regression model, we compared Excellence and Implementation scores between RR and SA applications across the 2023 research call (SA n=358) with those from the 2024/2025 calls (RR n=142, SA n=694). Intraclass correlation coefficients assessed reviewer-related variance, and exploratory analyses examined reviewers' confidence and disagreement levels. Preregistered Stage 1 protocol: https://osf.io/jq84x/overview (date of in-principle acceptance: 20/01/2026).Results: RR applications were not scored significantly higher than SA applications on Excellence (β= −0.08, 95% CI [−0.20, 0.03], p=.131) or Implementation (β= −0.04, 95% CI [−0.14, 0.06], p=.408). Excellence scores were slightly lower in the 2024/2025 calls than in the 2023 call (β= −0.08, 95% CI [−0.16, 0.00], p=.048), whereas Implementation scores did not change. Reviewer variability accounted for 18.3% of the variance in Excellence scores and 15.4% in Implementation scores, and was not greater for RR than SA applications. Conclusion: Findings do not support that choosing RR format yields higher assessed research quality at the application stage, but are informative for funders and journals developing their own RR models.