Anaesthetists’ Non-Technical Skills (ANTS): evaluation of a behavioural marker system † †Declaration of interest: The ANTS system was developed under research funding from the Scottish Council for Postgraduate Medical and Dental Education, now part of NHS Education for Scotland, through grants to the University of Aberdeen from September 1999 to August 2003. The views presented in this paper are those of the authors and should not be taken to represent the position or policy of the funding body.