I'm on holiday which means I've got time to work my way through the past exam papers that I've been hoping would solve themselves. I know that the mark schemes are available from the Ib and I'm not trying to provide an alternative to that, you should still get these and use them for marking trial exams etc. However when students are using the exam papers for revision they often require a fuller explanation than is given on the mark scheme. I do the papers on my tablet PC using journal then I take screen shots of the pages, crop them using paint.NET and save them as .png files which I upload to the web server where I they are displayed on a web page (example). I hide the images to make the page easier to navigate. Takes a bit of time but when it's done it's done.

So I'm fresh from from uploading the solutions to may 2011 paper 3 time zone 2. Subscribers can get it here. Fresh from doing the whole paper I have some general comments.

• some of the questions are incredibly long, particularly the  communications
• the questions are no where near of equal difficulty, the particles and relativity questions are way harder than the medical
• I think a good student would score well on medical without even doing the course
• students have to memorise the properties of particles
• sometimes its difficult to see how the marks are awarded
• doing past papers is a good way to know what is required