#Design practices
- Industrial design. The professional service of creating and developing concepts and specifications that optimize the function, value, and appearance of products and systems for the mutual benefit of both user and manufacturer (from the Industrial Design Society of America’s website).
- Interaction design. The focus is upon how people interact with technology. The goal is to enhance people’s understanding of what can be done, what is happening, and what has just occurred. Interaction design draws upon principles of psychology, design, art, and emotion to ensure a positive, enjoyable experience.
- Experience design. The practice of designing products, processes, services, events, and environments with a focus placed on the quality and enjoyment of the total experience.
#Discoverability and understanding are two of the most important characteristics of good design
Discoverability results from appropriate application of five fundamental psychological concepts:
- Affordances
- Signifiers
- Constraints
- Mapping
- Feedback
Affordance refers to the relationship between a physical object and a person. It’s the possible interaction between people and the environment. Some affordances are perceivable, others are not. If an affordance cannot be perceived, its presence needs to be signaled by a signifier.
The difference between affordances and signifiers are that affordance determine what actions are possible, while signifiers communicate where the action should take place.
#On affordances
Affordance is a UI which has the expectation of the interaction embedded in it. Affordances represent the possibilities for how a person can interact with something.
The term affordance refers to the relationship between an object and a person. A chair affords support, and therefore affords sitting.
Affordances are visual clues in an object’s design that suggest how we can use it. Affordances are the meat and potatoes of a visual user interface:
- A flat plate mounted on a door affords pushing.
- Knobs afford turning, pushing, and pulling.
- Slots are for inserting things into.
- Balls are for throwing or bouncing.
Perceived affordances help people figure out what actions are possible without labels or instructions. Affordances are relationships, not properties.
#Signifiers communicate interactions in your design
Signifiers signal things. Particularly what actions are possible and how they should be done. Signifiers can be signs, labels, and drawings placed in the world, such as the signs labeled “push,” “pull,” or “exit” on doors, or arrows and diagrams indicating what is to be acted upon or in which direction to gesture, or other instructions. Signifiers must be perceivable, otherwise they fail to function. Signifiers communicate how to use a design. Think about the bars on doors. People fleeing a fire would die if they encountered exit doors that opened inward, because they would keep trying to push them outward, and when that failed, they would push harder. The proper design is to change the design of doors so that they open when pushed.
#Provide appropriate feedback in your design
Ever watch people at an elevator repeatedly push the “Up” button, or repeatedly push the pedestrian button at a street crossing? Ever drive to a traffic intersection and wait an inordinate amount of time for the signals to change, wondering all the time whether the detection circuits noticed your vehicle (a common problem with bicycles)?
What is missing in all these cases is feedback: some way of letting you know that the system is working on your request.
Hospital operating rooms, emergency wards. Nuclear power control plants. Airplane cockpits. All can become confusing, irritating, and life-endangering places because of excessive feedback, excessive alarms, and incompatible message coding. Feedback is essential, but it has to be done correctly. Appropriately.
#How does the system image of your product look like?
How do we form an appropriate conceptual model for the devices we interact with? We cannot talk to the designer, so we rely upon whatever information is available to us: what the device looks like, what we know from using similar things in the past, what was told to us in the sales literature, by salespeople and advertisements, by articles we may have read, by the product website and instruction manuals. This combined information available to us we can call the system image. Good conceptual models are the key to understandable, enjoyable products: good communication is the key to good conceptual models.