This picture expresses the concept of "affordance", this comes from Kimbro.

"Affordance" is a term used by perceptual psychologists. Affordance is what an object suggests to us. For example, if you see a bench, you might think to sit down on it, or to lay down on it. Some doors have a panel on once side, and a handle on the other. If you see the panel, you think to push it. If you see the handle, you think to pull it. Perceptual psychologists use the phrase "object affordance" to talk about how objects make us think to use them.

Perceptual psychologists ask, "What is it about this object that makes people want to use it this way?" The object must talk to us with some sort of language. If we can understand this language, then we can make tools that tell us how to use them! We can also make tools that recommend some uses, and discourage others.

"Discouraging" sounds sort of odd: Why would a tool let people do something, but then discourage people from doing so?

One reason might be "because we can't do anything about it!" You can throw just about any physical object, even if you don't intend people to.

Another reason might be "because some people will actually need to use it that way." If you have a fire alarm, you want people to be able to pull it. But you only want them to pull it if there's an actual emergency.

The concept of social affordance:

Since Gibson's original idea of object affordances (See: WhatIsAffordance), software designers who create tools for communication and group interaction have come to speak of SocialAffordance. This expands the concept of designing affordances in physical environments to the development of software, and how it can afford certain types of interaction.

The concept hierarchy might look like: - WhatIsAffordance - object affordances o SocialAffordance - tools for communication, from phones to IRC to online communities