Although some conclusions could be drawn from frequency of citation, the list of
criteria developed in the initial Delphi round needed to be prioritised to identify the
most relevant evaluation factors. Thus they were fed back to the expert group, with
each respondent requested, in addition to identifying any errors, omissions and
duplications, to rate each factor using a five point continuous rating scale, from ‘‘1’’
meaning that the factor could be ignored to ‘‘5’’ meaning that consideration of the
factor was essential.