1. The Role of Prototyping
AN OVERVIEW BY JAMIE STARKE

2. Outline What is a prototype Why should we prototype
Benefits and Drawbacks of Prototyping
Where it is used
How to create a prototype
How Prototypes differ

3. What is a prototype A model of an eventual system
Interface prototyping usually includes visual aspects
Limited functionality or features

4. Why should we prototype
Obtain early feedback on design alternatives
Give concrete examples to elicit feedback
Show what is possible
Create better designs
Useful in communicating concepts

5. Benefits of Prototyping
Fast and Cheap (compared to the full system)
Elicit more and better feedback Early
Identify design problems before coding begins
Reduces cost of design errors (as they are identified earlier)
Encourages Creativity

6. Drawbacks to Prototyping
Viewed by some as a duplication of effort
Can give the impression that the product is nearly complete (depending on appearance of the prototype)
Not all ideas that can be prototyped are implementable.

7. Where Prototyping is used
Early
Gives concrete examples of what’s possible to discuss and elicit feedback
Helps when trying to elicit requirements
Helps ensure we get the right design
Midway
Useful for testing difficult concepts before solidifying design
Finding problems in difficult tasks, ensuring users can accomplish their goals
Helps to ensure that the design is right

8. How to create a prototype
Choose a task you are interested in Prototyping
What is the Goal of the task, what does a person want to accomplish
What inputs or assumptions are needed
That steps would be required by the user to reach the goal
Create screens for each step in the task
Don’t forget to make sure that any inputs or assumptions are taken into account

9. What information is needed for a Prototype
Goal: What is the user trying to accomplish, should be realistic
Input: What information or resources will the user need to accomplish the task
Assumptions: These are assumptions about the state of the system before you begin. May be interesting for error cases
Steps: What steps will the user need to perform to make it to the goal.

10. Exercise What is the Goal of the User?
You are building a new phone that can take pictures of a book’s barcode, and present the user with a “buy this book” page.
For this example, we are interested in the task of buying a book.
What is the Goal of the User?

11. Exercise What Inputs do we need?
You are building a new phone that can take pictures of a book’s barcode, and present the user with a “buy this book” page.
For this example, we are interested in the task of buying a book.
What Inputs do we need?

12. Exercise What Assumptions do we have?
You are building a new phone that can take pictures of a book’s barcode, and present the user with a “buy this book” page.
For this example, we are interested in the task of buying a book.
What Assumptions do we have?

13. Exercise What Steps does the user need?
You are building a new phone that can take pictures of a book’s barcode, and present the user with a “buy this book” page.
For this example, we are interested in the task of buying a book.
What Steps does the user need?

14. Example
Prototyping at this point can be divided among the team, which different people creating different screens, or collaborating on them.
Different alternatives to screens can also be created
We will divide the steps we came up with among the class (if we have time)

15. One possible solution
Goal: To order a copy of Paper Prototyping by Snyder
Inputs: Barcode for Paper Prototyping
Assumptions: Shipping and payment information stored in phone

16. One possible solution Steps: On main screen, open camera
Take picture of Barcode for Paper Prototyping
Buy “Buy Now” form
Place Order

17. How Prototypes Differ
Scope
Fidelity

18. Scope
Nielson, Usability Engineering, 1993

19. Scope
Scenario
Used to understand how the users will interact with the system
Used in early in design to elicit feedback without having to create a working prototype
The previous example would be considered a scenario
Nielson, Usability Engineering, 1993

20. Scope Vertical Prototype Reduced amount of functions
In-depth functionality for those few features
Allows for testing users under realistic conditions, without creation of the complete system
In some cases this means linking to the actual data
Nielson, Usability Engineering, 1993

21. Scope Horizontal Prototype
Used to demonstrate how the features fit together
Reduced functionality
Does not likely contain link to real data
Testing does not have a very high level of realism as the features lack functionality
Nielson, Usability Engineering, 1993

22. Fidelity Low Fidelity High Fidelity Low Cost
Useful for Requirements Identification
Evaluate multiple design concepts
Limited Usefulness for Usability Testing
Navigational and flow limitations
Poor detailed specification to code
Complete Functionality
Full Interactive
Look and Feel of final product
More Expensive
Not effective for requirements gathering
Time Consuming to create
Rudd, Low vs High Fidelity, 1996

23. Outline Why should we prototype Benefits and Drawbacks of Prototyping
Where it is used
How to create a prototype
How Prototypes differ