Seven Fundamental Design Principles

"Each of the seven stages indicates a place where the person using the system has a question. The seven questions pose seven design themes. How should the design convey the information required to answer the user’s question? Through appropriate constraint and mappings, signifiers and conceptual models, feedback, and visibility."

Don Norman highlights each principle with his questions for the designers to gain feedback from the target audience from what they have produced:

• What do I want to accomplish?
• What are the alternative action sequences?
• What action can I do now?
• How do I do it?
• What happened?
• What does it mean?
• Is this okay? Have I accomplished my goal?

Principle 1: Discoverability

Pilot Mountain State Park in Pinnacle, North Carolina has a Ranger Station with public restrooms. It is easy to discover the design of the doors at the entrance of the Ranger Station and the restrooms inside because the door handles on both sides of the doors are long rods that can be pulled. However, only one side of the door functions properly when the door is pulled. The product produces the goal of opening the door, but there is an alternative action which changes the function.

Principle 2: Feedback

Once a product is put out on the market or in the planning stages for launch, it is important to gain feedback about the product to ensure the design answers the question “what do I want the product to accomplish?” This will not only help the consumer but it will also help the company producing the product as they move forward. At the feedback stage, the designers should have learned about the alternative action of the door. It’s unlikely that they desired for only one rod to open the door.

Principle 3: Conceptual Model

The conceptual model—when designed properly—will “lead to understanding and a feeling of control.” As consumers, we are naturally inclined to respond best to products when we are in control, and the product fulfills our expectations.

When we feel that something is not in our control, we tend to avoid that object or task altogether. 

Principle 4: Affordances

“Affordance refers to the relationship between a physical object and a person. E.g., a chair affords (‘is for’) support and, therefore, affords sitting.” In our example, there was affording for pulling, but there wasn’t affordance for pushing. The next step is to ask “what happened?”

Principle 5: Signifiers

Affordance and signifiers play off of each other. There needs to be a level of intuition to the function of the product. Signifiers are intuitive ways for the product to be used by the consumer (i.e. the rods which are pulled to open the door). These signifiers “ensure discoverability and will allow for feedback to be properly communicated and intelligible.” 

Principle 6: Mappings

The design of the door handle from the State Park was not great but it could have been worse. What if there was a rod near the hinges of the door? The door will not open, but this will take a long time for the signifiers to catch up to the consumer to afford the door to open by pushing on the opposite side of the door from the rod. Mapping out the successes and failures of the design will help to inform future direction.

Principle 7: Constraints

Constraints help “guide actions and interpretation.” Without constraints, there is a waste of resources that create a new level of frustration. Keeping your product simple and under a constraint (often adhering to convention, i.e. a door handle for a public restroom as opposed to a knob) will lead to a simple solution to allow the consumer to accomplish his or her goal.

Two forms of Innovation: Incremental and Radical

"There are two major forms of product innovation: one follows a natural, slow evolutionary process; the other is achieved through radical new development [;however,] the most common and powerful form of [change] is actually small and incremental."

When looking back in history, products produced can be seen to have a steady progression. A product is made, for example, the steam engine, and over time someone says, “I believe there is a better way.” The product goes through experimentation and continues to have changes made. Believe it or not, the first steam-driven vehicle was built in the 1700s and the first commercial vehicle was produced in 1888. Things built normally follow this progression of “small and incremental change.”

However, there are changes in paradigms which come with radical innovation. “Radical innovation starts fresh, often driven by new technologies that make possible new capabilities.” The second factor in radical change or innovation is changing the meaning or narrative that consumers are telling themselves. The story must change for radical innovation to occur.

Eliminate the Potential for Human Error

"Instead, talk about communication and interaction: what we call an error is usually bad communication or interaction."

Norman discusses the interaction and communication between machines and humans.  Humans tend to have—and I have yet to see a machine have—emotional intelligence.  So, when operating on the principles of design, a machine and a human can work together to produce efficiency, but a human must be able to interact with the product  emotionally and experimentally in order to eliminate design flaws. A human must touch, see, and play with the product under his or her own intuitive understanding in order to combat future human error.