About the Authors

Keith Goatman

Affiliation School of Medicine and Dentistry, University of Aberdeen, Aberdeen, Scotland

Amanda Charnley

Affiliation St. George's Hospital, London, United Kingdom

Laura Webster

Affiliation St. George's Hospital, London, United Kingdom

Stephen Nussey

Stephen.Nussey@stgeorges.nhs.uk

Affiliation St. George's Hospital, London, United Kingdom

Competing Interests

The authors have read the journal's policy and have the following conflict: KAG is employed by the University of Aberdeen who have licensed the automated grading software to Medalytix. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials. The remaining authors have declared that they have no competing interests.

Author Contributions

Designed software for external arbitration exercise: KAG. Conceived and designed the experiments: SSN KAG. Performed the experiments: SSN KAG AC LW. Analyzed the data: KAG SSN. Contributed reagents/materials/analysis tools: SSN. Wrote the paper: KAG SSN.