Prototyping
2. Measuring Goals
dependent on the falsifiability of usability requirements
Cost of Change over Time
Jakob Neilson 100x more expensive to make changes after they've been coded up biggest improvements in user experience come from gathering usability data as early as possible
prototype example
Jeff Hawkins' block of wood (palm pilot)
Video Prototyping Steps (4)
1. outline 2. obtain equipment 3. focus on MESSAGE 4. film
Prototyping Strategies (4)
1. paper prototypes 2. video prototypes 3. digital mockups 4. wizard of oz
Lessons from IDEO Camera
1. prototypes are almost always incomplete 2. goal is to SIMULATE specific aspects of the design//acquire knowledge regarding these targeted aspects
Cons of WOO
1. simulations may represent imperfect/impossible technology 2. wizards require training and can be inconsistent 3. playing wizards can be exhausting 4. some features are difficult/impossible to simulate 5. may be inappropriate in seom venues
Low Fidelity Strategies
- Storyboarding - Video Prototypes - Paper Prototyping
Video Considerations
- audio not necessary - interface fidelity can differ - show success and failure - don't spent too much time editing
High fidelity
- coded models - physical models **still functionally incomplete
Basic prototyping process
- define questions regarding design and building something to answer those questions
Collecting Data with WOO
- practice first - recruit users later - 2 roles: facilitator = provides tasks and takes notes, wizard = operates interface
Pros of Video Prototyping
- ties interface design to tasks - great communication tool (portable, self-explanatory) - cheap and fast - can serve as a 'spec' - can be any level of fidelity
Pros of Paper Prototyping
- very fast evaluation and testing - easy to change and adapt - user involvement at an early stage - encourages creativity
when to use WOO?
- when there is advanced technology involved and there is no time to build it - when you haven't determined how to best implement a feature
Paper Materials
- widgets -connectors - drawing
Strength of Prototypes
1. Low fidelity 2. High fidelity
Storyboarding
ALL about tasks and task flow, not specific interface elements
Wizard of Oz
an interactive application without much code (only front interface coded up) that allows designers to get feedback from real users - human simulates system functionality behind the scenes
Unknown Unknowns
aspects of a design that you don't know are open issues
Known Unknowns
aspects of a design that you know you don't understand yet and wish to learn
Paper Prototyping
literally use paper to produce a potential interface (moveable pieces)
Prototyping over time
more prototypes in early stages --> less as time goes on (higher fidelity)
what should storyboarding convey?
setting: people involved, environment, tasks being accomplished sequence: steps involved satisfaction: motivation, what can be accomplished, what need does system fulfill?
WOO examples
speech recognition - human listened to user commands and adjusted interface accordingly intelligent tutors Robi (cute robot guy)
Paper Considerations
- keep materials in one place - work quickly and make components reusable - if something is difficult to simulate, use verbal description - backgrounds can provide context - can mix and match hardware and software - include familiar operational elements when appropriate
Video Prototyping
video including the WHOLE task (with motivation and success) that draws on tasks you observe
1. Prototyping Goals
presented by usability goals and requirements
3. Minimum Work Necessary
strip out unnecessary features - square root graph (x-time spent, y-learning)
prototyping definition
the rapid creation of an approximation to a design idea for the purpose of retrieving feedback and knowledge
Digital Mockups
- looks like the actual digital device (or site) with limited functionality **can use pwpt to simulate design
Wizard of Oz Motivation
- need feedback, but can't get feedback unless something is built - what if your system is complicated?
Low fidelity
- paper prototypes (physical rearrangement) - drawings (less flexible)
Pros of WOO
1. fast/cheap means more iterative prototypes possible 2. easy to create multiple variations 3. more "real" than paper 4. id's bugs and problems with current design 5. places user at center of development 6. can envision future technology needed to build application 7. designers learn by playing wizards
Types of prototypes (3)
1. feel (and look) 2. implementation (how does it work?) 3. role (experience?)
Reasons to Prototype (3)
1. gain insights to user behavior 2. communicate ideas to other teammates and stakeholders 3. collect data for arguing the best design choice
Pros of Storyboarding
1. holistic focus 2. avoids commitment to a particular UI 3. helps get all stakeholders on the same page
WOO Steps
1. map out scenarios and application flow 2. put together interface skeletons 3. develop "hooks" for wizard input 4. put it all together 5. rehearse wizard role with a colleague
Prototyping Rules
1. not required to be complete 2. should be easy to change 3. should be disposable
Types of user feedback
1. think aloud (speak as performing tasks) 2. retrospective (discuss after task is performed) 3. heuristic evaluation (experts watching interaction unfold)
Prototyping Process (3)
1. what are your goals/what do you wish to learn? 2. how can you measure whether or not that goal has been met? 3. what is the MIN amount of work necessary to produce, measure, and learn from your prototype?
Big prototypes
Walter Teague's airplane cabin, Apple Store mockup