The Design of Everyday Things by Donald Norman

1. The author's key points in this chapter is that consumers tend to purchase goods with many useful functions and designs, but would not know how to use it due to its complications. Donald Norman explains that many everyday things are poorly designed. The three problems that consumers deal with are visibility, mapping, and conceptual model. There should be hints or images to how to operate things such as doors as well as having a multi-use control. Also, people already have a fixed idea on how an object should be used.
Many everyday things are lacking feedback. Consumers are impressed by the features that lured into purchasing it. When a person brings an item home, they realized that it is difficult to use. This is because a good design should never have a control with more than one action.

2. An object I had difficulty using was my watch. My watch has one knob but many features. To change the time, I had to pull the knob and turn it clockwise or counterclockwise. However, if I want to set my alarm clock I have to pull the knob twice and turn it clockwise or counterclockwise and then push the knob back in. The difficulty of mt watch arises from the Mapping principle. One control accounts for two settings. I often find myself pulling the knob too hard and end up setting an alarm clock instead of changing the time. Visibility is also an issue because I cannot figure out whether I have pulled once or pulled twice on my knob, until I have noticed the hands move.

3. The iPod has good visibility. Each button had a play, stop, pause, forward, and back sign. The scrolls were naturally interpreted that as your fingers shift right the songs will go down the list and vice versa. Another natural signal was the faster you scroll around the scrolling wheel the faster the speed will accelerate.
The mapping of the iPod is good because the number of actions and the number of controls were very close. Most buttons are one use buttons, and is very similar to electronics.
The conceptual model of the iPod is designed very well because the buttons were simple enough that it constraints a person from using it incorrectly. Therefore, the iPod is well designed and part of the reason for that is because Steve Jobs encouraged many feedback, trials, and revision.