The design of everyday things. Knowledge in the head and in the world

Here I provide my thoughts that popped up during the reading of the third chapter “Knowledge in the head and in the world” from “The Design of everyday things” book.

Key take aways

• there is always knowledge in the world and in the people heads. As a designer you control what knowledge is put in the world. And here is the challenge to put enough information in the world by matching what people have in their heads for successful usage of the product
• knowledge/models shouldn’t aim for 100% accuracy, but for practical sufficiency
• people are not great in remembering arbitrary things they will create structures to transform them into meaningful things, help them, guide them
• different groups of people will use different subsets of knowledge from the world and all these groups will succeed in their use-cases

Simplified models

Again author shows in a simplified way how people minds work. It’s not 100% accurate to the current scientific understanding but it’s good enough for us to use. If models that are not precise are good enough and can be learned easier, they should be utilized.
This principle works well when we’re talking about using some devices, until people can successfully use them it doesn’t matter much how approximate the model in their head.
There is however, a trap with this approach for general knowledge. People often learn simplified models and think they understand how everything works.
Using imprecise models isn’t a problem as a concept, as long as you acknowledge and stay aware of it.

Knowledge in the world

It’s a tricky one, if users have more knowledge in the world — it’s easier for them to pick up things. But it’s always challenging to match what knowledge people already have in the head and provide them good enough knowledge in the world, so they are not overwhelmed.
Good catch with change management. You need to realize that usually there is more knowledge in the world than it’s needed for performing actions. And it’s important to know which part of this knowledge is used, so you understand what changes you can safely make and which are harder to change.
A good example that many people have experienced with UI changes: when you being using software, you read labels on buttons(knowledge in the world) However, as you master the software, you don’t need to read labels constantly. Instead, you remember that the needed button is located in the left top corner, right after another button(knowledge in the head). You are still using some knowledge in the world(how buttons are located relatively each other) but as you can see this knowledge is way more limited than we actually have in the world. Now if designers are not good enough in change management, they might just simply swap the buttons and for them it would be fine, because “we have labels on the buttons”, and for new users it would make no difference, but for the old users — they don’t use labels, they use “position” information.