Q 1. There are many different kinds of vending machines in the world. Each offers a range of goods, requiring the user initially to part with some money. Following photos of two different vending machines, one that provides soft drinks and the other a range of snacks. Both use an instructional mode of interaction. However, the way they do so is quite different.

Please answer the questions: What instructions must be issued to obtain a soda from the first machine and a bar of chocolate from the second? Why has it been necessary to design a more complex mode of interaction for the second vending machine? What problems can arise with this mode of interaction?