Presentation to a webinar of the Open Distance Learning Association of Australia. There's an MP4 recording of this presentation and two others at https://sas.elluminate.com/site/external/playback/artifact?psid=2013-10-30.1257.M.DC6A1EF286808F12D18EB8598CC79A.vcr&aid=57170. More details of the ODLAA 2013 webinar series at http://www.odlaa.org/index.php?option=com_content&view=article&id=82&Itemid=109.