Messing about is a playful exploratory activity where students construct a modestly-working device of the kind they will be redesigning later and tinker with it to discover its capabilities and ways of making it better, explore the characteristics of materials they will be using, or play with devices like those they will be designing to see what factors affect how well they work. The goals of messing about are to get students intellectually engaged with the challenge they will be addressing and at the same time prompt them to ask the kinds of questions whose answers will help them understand science content better.