WEEK 2 – AFFORDANCES 

Norman, D 1998, The design of everyday things , Basic Book, New York (Sections: Preface vii-xv; Chapter one pp 1-13; Chapter 4 (constraints) pp 81-87; (computers) pp 177-186).

Norman, D 1999, ‘Affordance, conventions and design (Part 2)’, Nielsen Norman Group, viewed 1 April 2012, http://www.jnd.org/dn.mss/affordance_conv.html

The design of everyday things presents us with the idea that far too many items in the world are designed, constructed and foisted upon us with no understanding or even care for how we will use them. Norman states that while the problem might sound trivial, it is the difference between pleasure and frustration. Donald Norman makes reference to perceptual psychologist J.J Gibson’s original notion of “affordances”, applied to the concept of design practitioning, which focuses on making the end users of a product or service an integral part of the design process. The design of everyday things provides an insight into and provides an insight into everyday things that are deliberately, unremarkable, outrageous or other ill informed or intuitive to use. Norman was perplexed and fascinated by the fact that people come across new things everyday, yet know how to use them. Norman argues that if an object is well designed, you don’t have to learn how to use it after learning how to use it once – yet this isn’t the case with a lot of every day items. Norman wished to improve the design of everyday objects by putting forward some principles for designers to follow. There were a number of concepts but it was affordances that stuck out to most designers. We learn this concept of the “Norman Door”, in The design of everyday things which is the recognition of the lack of attention paid by the user.

What are affordances? Norman outlines that the term affordance refers to the perceived and actual properties of the thing, primarily those that determine how a thing could possibly be used. Affordance refers to the properties of an object and the person, and is the relationship between the object and the person and what the person can do with the object. The affordance is jointly determined by the properties of the object and the abilities of the person interacting with the object. Norman suggests that a person forms a ‘conceptual model’ of how things are used and this is comprised by the affordances.  

Affordance, conventions and design (Part 2) presents us with further developments on these ideas presented in The design of everyday things by Norman – diving into the explanations of affordances, constraints and conceptual models.

Norman explains in this article that the word “affordance” was originally invented by J.J Gibson to refer to the actionable properties between the world and an actor (a person or animal). To Gibson, affordances are relationships. They exist naturally; they do not have to be usable, known or desirable.

Norman explains that his previous work was about “perceived affordance”, stating – when I get around to revising POET, I will make a global change, replacing all instances of the word “affordance” with the phrase “perceived affordance”. Norman discusses that the designer cares more about what actions the user perceives to be possible than what is true. Moreover, affordances, both real and perceived, play very different roles in physical products than they do in the world of screen-based products. In product design, where one deals with real, physical objects, there can be both real and perceived affordances, and the two sets need not be the same.

When Norman moved to England to study Applied psychology Unit in Cambridge. His struggles with British water taps, light switches, and doors inspired him to write “The Psychology of Everyday Things”. A major theme of this was the attempt to understand how we managed in a world of tens of thousands of objects, many of which we would encounter only once. When you first see something you have never seen before, how do you know what to do? Norman decided the answer was that the required information was in the world: the appearance of the device could provide the critical clues required for its proper operation. Norman argued that understanding how to operate a novel device had three major dimensions: conceptual models, constraints, and affordances. Normans Conceptual Models point out that good design is also an act of communication between the designer and the user. This can be broken down:

• Feedback: In design, it’s important to show the effect of an action.
• Constraints: The surest way to make something easy to use, with few errors, is to make it impossible to do otherwise. To do this, we constrain our choices.
• Affordances: A good designer makes sure that appropriate actions are perceptible and inappropriate ones invisible.

Norman then moves on to explain constraints and conventions. Normans conventions and constraints explained and understood in five different sections:

• Physical constraints: are closely related to real affordances: For example, it is not possible to move the cursor outside the screen: this is a physical constraint. Locking the mouse button when clicking is not desired would be a physical constraint. Restricting the cursor to exist only in screen locations where its position is meaningful is a physical constraint.
• Logical constraints: use reasoning to determine the alternatives. Thus, if we ask the user to click on five locations and only four are immediately visible, the person knows, logically, that there is one location off the screen. Logical constraints are valuable in guiding behaviour. It is how the user knows to scroll down and see the rest of the page. It is how users know when they have finished a task. By making the fundamental design model visible, users can readily (logically) deduce what actions are required. Logical constraints go hand-in-hand with a good conceptual model.
• Cultural constraints: are conventions shared by a cultural group. The fact that the graphic on the right-hand side of a display is a “scroll bar” and that one should move the cursor to it, hold down a mouse button, and “drag” it downward in order to see objects located below the current visible set (thus causing the image itself to appear to move upwards) is a cultural, learned convention. The choice of action is arbitrary: there is nothing inherent in the devices or design that requires the system to act in this way. The word “arbitrary” does not mean that any random depiction would do equally well: the current choice is an intelligent fit to human cognition, but there are alternative methods that work equally well.
• Convention: is a constraint in that it prohibits some activities and encourages others. Physical constraints make some actions impossible: there is no way to ignore them. Logical and cultural constraints are weaker in the sense that they can be violated or ignored, but they act as valuable aids to navigating the unknowns and complexities of everyday life. As a result, they are powerful tools for the designer. A convention is a cultural constraint, one that has evolved over time. Conventions are not arbitrary: they evolve, they require a community of practice. They are slow to be adopted, and once adopted, slow to go away. So although the word implies voluntary choice, the reality is that they are real constraints upon our behaviour. Use them with respect. Violate them only with great risk.
• Symbols and constraints: are not affordances. They are examples of the use of a shared and visible conceptual model, appropriate feedback, and shared, cultural conventions.

Norman closes this article with How do you know if the user shares the conventions? Why, with data, of course. This is something that can not be decided by arguments, logic, or theory. Cultural constraints and conventions are about what people believe and do, and the only way to find out what people do is to go out and watch them. Not in the laboratories, not in the usability testing rooms, but in their normal environment… I still hear far too much dogmatism about what people really “want,” what they “believe,” or how they “really” behave, but I see very little data. It doesn’t take much data. My partner, Jakob Nielsen, has long argued that you can get these data at a discount: three to five people will give you enough for most purposes (Nielsen, 1993, 1994). But they need to be real people, doing real activities. Don’t speculate. Don’t argue. Observe.