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Science Forum: Improving preclinical studies through replications

  1. Natascha Ingrid Drude
  2. Lorena Martinez Gamboa
  3. Meggie Danziger
  4. Ulrich Dirnagl
  5. Ulf Toelch  Is a corresponding author
  1. Department of Experimental Neurology, Charité–Universitätsmedizin, Germany
  2. BIH QUEST Center for Transforming Biomedical Research, Berlin Institute of Health, Germany
Feature Article
Cite this article as: eLife 2021;10:e62101 doi: 10.7554/eLife.62101
1 figure and 1 table


Increasing different forms of validity (internal, external and translational) during a preclinical research trajectory.

This schematic shows that internal validity (green line) is higher than external validity (orange) and translational validity (blue) at the start of a preclinical research trajectory (left), and that evidence from different types of experiments can increase different types of validity. For example, evidence from exploratory studies can increase internal and external validity, and evidence from between-lab replications can increase translational validity. C1, C2 and C3 are decision points where researchers can decide to refine the current experiment (yellow arrow), stop the trajectory (red arrow), or proceed to the next experiment (green arrow).


Table 1
Overview of three large-scale replication projects in biomedical research: Reproducibility Project: Cancer Biology (RPCB); Brazilian Reproducibility Initiative (BRI); Confirmatory Preclinical Studies (CPS).
Selection of samples to be replicatedMain findings from 50 high impact citations/publications in cancer researchReplication of 60–100 experiments from research articles of Brazilian studies in different clinical areasTwo-step review process of proposals results in twelve projects
Selection of experimentMain finding from published studiesExperiments using five pre-defined methodsOwn experiments
Replicate own resultsNoNoYes
Exact ProtocolsYes (consulting original authors)NoYes
Blind to initial resultsNoYesNo
Pre-registrationPre-registered study and individual Replication ProtocolsYesYes
Multi-site replicationNoYesYes

Data availability

No data was generated.

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