Prototype

Prototype Fidelity

Fidelity: how faithful is the prototype to the final system's look and feel?

Low fidelity:

• Does not resemble final product, operation slower
• Faster to create and iterate
• Low-investment, encourages experimentation

High fidelity:

• Looks and operates like real product
• More accurate
• False sense of completeness and focus on details

Prototype Technologies

From early to late:

• Paper: nothing is automated
• Presentation software: choose-your-own-next-screen
• Dedicated prototyping tools (variable)
• HTML/CSS/JS: interactive links but no "guts"
• Final system platform/technology: interaction + guts

Prototyping Functionality

Question: How do you prototype a system that has not actually been implemented yet?

Answer: The Wizard of Oz

Prototyping: Breadth vs. Depth

• Breadth: demonstrates the amount of features, options and commands. Each feature is rendered, but cannot be followed very far.
• Depth: shows interactivity and functionality. All but a few critical features are inactive "dead ends".
• "Horizontal prototypes (favors features)" vs. "Vertical prototypes (favors functionalities)"

Prototyping Scenarios

It is expected that not every interaction or path will be explored in every prototype.

Constrain user interaction and the prototype implementation to yield the type of feedback that would be most useful.

Why/what are you prototyping?

• Proof of concept
• Visual design, screen layout, information display.
• Form & physical attributes
• Interaction, workflow, tasks
• Functional model
• Difficult, controversial, critical areas

Paper prototyping

• Paper is cheap, easy and universally understood
• Paper is instantly customizable, malleable, and unconstrained
• Encourages creativity