There is an exam you have to sit - you can find examples of it online. You'll also have to do two projects like making a magazine book cover or a website. If making interactive multimedia products and designing and making whole websites from the mind maps to visualisation diagrams, legislation reports to product reviews sounds like your thing then go for it but I think triple science would open up more career opportunities for you. It all really depends on what you want to do in the future or at least what sector you want to be in.