Hi all I recently discovered that there are people who haven't heard of the flipped classroom. http://learnandteachstatistics.wordpress.com/2013/06/10/the-flipped-classroo m/ Now that won't be you! Thanks for all the suggestions last week for data sets. I can see the problem is not going away any time soon. Nicola =========================================================== Dr Nicola Ward Petty Aka Dr Nic Statistics Learning Centre http://statslc.com/ Resources, videos, blog, help - you can find it all at Statistics Learning Centre. You may leave the list at any time by sending the command SIGNOFF allstat to [log in to unmask], leaving the subject line blank.