for those of you who were at the Seminar in Cardiff, this extensive article refers to a lot of the issues discussed in Prof. Apperley's excellent presentation.
Take a look at the home page for the link to the full article.
Sandy
Apparently the link does not take you to the full article.. try this link to the PDF
http://download.journals.elsevierhealth.com/pdfs/journals/0889-8588/PIIS0889858811001018.pdf
Sandy