ABSTRACT
(This is an overview of what I hoped – or planned – to say for my plenary talk at Interface 2011, 27 July 2011, UCL London (https://www.interface2011.org.uk" xmlns:xlink="https://www.w3.org/1999/xlink">https://www.interface2011.org.uk). I'm not a fan of reading from the script, so may have deviated, hesitated, repeated, and elided on the day).
