Slide 5 [name=REG] Is anyone else working with this UCL/UCLH team? Put your names here (Andrew: I am not but i would be interested in healthcare work) Slide 6

I think, overall the paper is written well. I think the improvements are mainly about coherence, creating the flow and most importantly placing concepts in context in every part of the paper. May Who is paper targeted to? The section about non-imaging datatypes is to me, the weakest section of this paper. The section about metrics is the strongest. Do we really need the non-imaging data section section to be as elaborate as it is? Some parts of the section elaborates heavily on foundation concepts, but also makes sweeping generalisations. For example the definition of non-imaging data can be complex with theoretical definitions. Is DateTime a data type separate from continuous and categorical values? Suggestion: Find references with definitions of these data types. Overall, storyline is not yet coherent; reader needs reminder about context of concepts throughout paper. Suggestion: Put introduction paragraphs for each section and subsection, to describe what the sections are about and why they are relevant and its context within the paper. Enumerate subsections so they don't come as a surprise. Put summary paragraphs after each section. Iain