Ocarina’s interface embodies traits of the original instrument, whereas Perry Cook’s coffeemug and its interface are not related to any preexisting instruments. Given these two examples, I am not sure that the principles in chapter 5 can be applied to objects outside instruments so very easily. But I do agree that the introduction of the computer allows for new ways of mapping input to output and creation of entirely new products who lack any analog counterpart. When creating new computer products who have an analog twin, I think that we need to address this similarity and create an interaction that resembles the one users know from the original object. If we fail to do so, the expected and the actual interaction will clash and lead to errors and frustration during usage.
However, if we design new computer products and software, we are free to experiment with the kind of interaction that feels right given the functionality of the object. That makes me wonder if all functionality affords a certain kind of interaction whether we know it or not. The chapter hints at the idea that good mapping is not a simple rule to follow but requires a certain intuition and must primarily feel right. Maybe an ideal interaction between human and functionality is pre-inscribed in every new product. After all, the human mind and our bodies work in a certain way, and we learned to use them to interact with the world around us in a certain way. Maybe our job is not to design new interactions, but to uncover the inherent interaction based on physical and cognitive constraints.
And this hypothesis in some sense ties into “Principle 5.18 Re-mutualize!”. Maybe the given parameters such as input, logic, presence, output, and experience afford a certain interaction (& mapping).