This chapter starts by explaining the 4 constraints: Physical, Cultural, Semantic and Logical. One example which comes to mind is the USB stick. It has physical constraints so that it can be entered in the one way, but this leads to trying one way and when it doesn’t fit in you try the other way. However, through knowledge of the world, some know that the two open holes on the side need to point up when inserting. With this information, one can insert the USB in a single try for horizontally placed ports. For vertically oriented ports it will still remain trial and error.
Next he discusses on the problems of doors, switches and faucets. The issue with switches is highly relatable. When building the ground floor of my house, the switches of the living room, dining room and pantry (around 15 switches) were located in one place. I somewhat mapped them room wise, but still you need to flip a few switches to get the correct one. The ideal solution would be to have a touch screen display which shows the location of the light. Also, the activity centered controls which Don mentions can be implemented in homes so you have few templates according to your needs. This can be seen in most smart home apps in the name of ‘Scenes’ .
With regards to faucets, there is absolutely no standard for thems here in my country. So if you go to a restaurant, hotel or even a friends house, you would most probably be confused on how to operate it. Most hotels and restaurants add a signifier in the form of a small poster on how to operate it.
Finally, he lists down the constraints that force a desired behaviour. Forcing functions and Lock ins are frequently seen in digital applications. For example some mobile apps would force you to turn on mobile data or location services to start using the app.
The lack of clear communication among the people and organizations constructing parts of a system is perhaps the most common cause of complicated, confusing designs
One final note on the destination based lift. I haven’t got a chance to experience one, but I believe it would be more confusing than the current lifts. Is this because I am used to the convention?