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“Wizard of Oz” Prototyping

4/13/16 HCC 613

Dr. Michele A. Williams

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A Little About Me…

•  Current: Postdoctoral researcher with a focus on accessibility research and UI design

•  Prior Industry Experience: Accessibility Analyst, VUI Designer

•  Education Background: Computer Science, Software Engineering, HCI

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The Wizard of Oz…WhatDorothyandgangini/allysaw.

Whatwasreallyhappening(thanksToto).

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Wizard of OzPrototyping technique for an interactive system that uses human operators to simulate machine behavior1

TheUser&Facilitator TheWizard

1StevenDow,StanfordHCIGroup,hOp://designclinics.pbworks.com/f/WOz-lecture.key.pdf

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Why Use WOz?

•  To test/confirm system design including alternative designs.

•  Can be used for rapid prototyping and ideation. •  Saves development costs if unsure of interaction

design. •  To find potential design issues prior to

development. •  To communicate system goals and functions with

stakeholders.

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When to Use WOz?

•  Early and often if possible. •  Prior to any substantial programming. •  Once you have enough functionality ideas to

implement an end-to-end solution (that is, more than just a general idea).

•  At stages where you want user input on design decisions.

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Wizard of Oz Implementation1. Design an interactive system

–  Determine system objectives. –  Decide appropriate functionality. –  Design what it will do – literally.

2.  “Build” a front-end interface –  Make something users feel is a real

system. Fake it ‘til you make it!

3. Create protocol –  Determine role players - “wizard”,

“moderator”, “facilitator”, “observer”. –  Determine equipment needed to

simulate realistic interaction.

–  Script user tasks and researcher actions (in detail, including error cases).

–  Determine usability measures – what are you testing? (This is 729!)

4. Run the test with users –  Run the usability test as scripted. –  Collect appropriate usability

measures (pass/fail, task completion, think aloud thoughts, surveys).

5.  Iterate design based on findings –  Evaluate what you learned and how

you want to make changes based on the findings.

–  Do this again if needed/appropriate!

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Discussion Question

What are some benefits of using a WOz test? •  Test complex or extremely new ideas that would

be hard to prototype (e.g. complex human-like reasoning).

•  Easier and cheaper to make changes, or even implement rapid prototyping.

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Discussion Question

What are some downsides of WOz prototyping? •  System may appear too polished and users may

not give detailed feedback. •  It’s expensive to implement a full system and

then “throw it away”.

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Discussion Question

What are some hindrances to completing a WOz? •  Money!!!

•  Who pays for the prototype (versus the ‘real’ system)? •  Who pays for the design and code changes? •  Who pays for multiple usability tests (WOz and final or even

more)?

•  Management may question why an “expert designer” needs this step.

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Time to try it!Task: Design & test a blind navigation aid system that describes surroundings Setting: Galleria mall in Baltimore (indoor shopping mall) Participants: Blind adults using white cane Considerations: •  Scenario •  UI design •  Equipment (recording and rendering)