An agile approach to iPhone design:
Paper prototyping + user testing
Suzanne Ginsburg, Principal
suzanne@ginsburg-design.com
Tuesday, April 21, 2009 1

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About Me
• More than thirteen years of experience designing software
• Six years in the Communities & Communications group at Yahoo!
• Three years consulting on my own (startups, in-house, design agencies)
• M.S. in Information Management from UC Berkeley’s iSchool
• Certified Scrum Master; participated in Agile pilot at Yahoo!
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Project Background
• A few months ago, I started sketching ideas for an events related iPhone app
• Before investing time & money on development, I wanted to get user input on
the concept.
– Were prospective users interested in the idea?
– What features & functionality would make the service most compelling?
– How would they respond to the presence of ads?
– Did the high-level information architecture make sense?
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Approach
Develop a paper prototype
+
Test prototype with prospective users
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What is a Paper Prototype?
• Format can be hand-drawn sketches or
screenshot printouts
• Fast & cheap way to incorporate user feedback
into designs.
• Developer/designer plays the role of “computer”
& simulates how the UI will behave
Posted by typeweight on Flickr
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What is a Paper Prototype? (cont’d)
When compared to high-fidelity testing, Jared Spool, the founder of User
Interface Engineering, describes it the following way:
“We think of paper prototyping as the course-grain sandpaper and
electronic-version testing as the fine grain. Once we’ve used the
paper prototypes to validate what each screen contains and how it
will work, we then move over to the electronic version to fine tune
the look and feel.”
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What are the benefits?
• Design changes can be made on the fly
during usability tests
• Usability participants may be more
comfortable being critical of a paper
prototype
• Making big conceptual changes early on
will save time & money
Posted by typeweight on Flickr
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What are the benefits? (cont’d)
“The most common estimate is that it’s 100 times cheaper to make a change
before any code has been written than it is to wait until after the
implementation is complete.” -- Jakob Nielsen
Testing ticketing system in Oslo; Posted by etunko on Flickr
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What types of projects are suitable?
Consider the project stage:
• Great for testing a completely new design
• Also works for changing parts of an existing design
• If you want to test an existing product, you might as well test the real thing
And the project domain:
• Works well for most productivity applications
• Good for some aspects of content-rich sites
• Can work for gaming; highly dependent on game type
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What types of issues can you explore?
• Concepts. Do they understand the key concepts?
• Terminology. Do they understand the terms in the UI?
• Navigation. Does the flow match what users expect?
• Content. Does it provide the right level of information?
• Page layout. Is content organized as users expect?
• Functionality. What additional features are desired?
Harder to address: Technical feasibility; download
time or other response times; scrolling, swiping; colors
Posted by timo on Flickr
and fonts
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What tools can you use to build paper prototypes?
Options are endless:
• Pen + paper: Combine with stickies, markers, &
other readily available office supplies.
• Sketching applications: Omnigraffle,
BalsamIQ, Visio (Note: Omni & BalsamIQ have
nice iPhone stencils.)
iPhone sketch created with Balsamiq
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iPhone Stencils: Graffletopia
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Pencil and Paper Prototype: Things iPhone App
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Next, User Testing
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Paper Prototype: Sample Usability Timeline
Planning Recruiting Study Findings
2 days 3 days 1-2 days 1 day
This one-week timeline is very aggressive & has a number of built-in assumptions:
• Planning: Assumes that the prototype has already been developed.
• Recruiting: Assumes recruiting requirements are relatively straightforward.
• Findings: Assumes that “quick” findings are sufficient for team.
Note: If you work with an agency or rent lab space, expect these times to double at
minimum. Costs will also be much higher (recruiting + lab can cost $5000 for 2
days; facilitation and analysis are separate line items)
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Paper Prototype: Usability Planning
Planning Recruiting Study Findings
2 days 3 days 1 day 1 day
Your test plan should include:
• Purpose • Test environment/equipment
• User profile • Test monitor roles
• Evaluation measures
• Method (test design)
• Report contents and presentation
• Task list
List is from, Handbook of Usability Testing, Jeffrey Rubin
Templates can be found at Society for Technical Communication:
http://www.stcsig.org/usability/resources/toolkit/toolkit.html
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Usability Testing Equipment: Fancy Lab
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Usability Testing Equipment: DIY Style
If you’re planning to do testing in-house, here are
some tools for recording your session
• Voice: iPhone has plenty of recording apps (e.g. iTalk
from Griffin)
• Photos: Bring camera to capture artifacts and take
participant photo (with permission)
• Video: Valuable if you need to report back to team
members or executives (also get permission)
• Elmo: Used to project paper onto monitor for viewing &
recording; these can be rented.
Handy dandy Elmo
Or you can go the basic pen & paper route.
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Paper Prototype: Usability Recruiting
Planning Recruiting Study Findings
2 days 3 days 1 day 1 day
Recruiting tips:
• Goal is to find participants that meet your user profile (5-8 recommended)
• Characteristics to consider may include: age, gender, education, occupation, computer
experience, product experience.
• Can use outside agency ($200/head) or do it yourself.
For my project:
• Recruited iPhone users who regularly attend certain local events and had downloaded at
least one iPhone app.
• Created screener with SurveyMonkey; posted on Craig’s List for $75.
• Participants were offered $50 for one hour; over 200 responses in one day.
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Paper Prototype: Usability Study
Planning Recruiting Study Findings
2 days 3 days 1 day 1 day
Study Tips:
• Facilitating sessions is harder than it looks; if you can’t do it, hire someone.
• Use the “think aloud” protocol; the goal is to listen and observe, not demo your product.
For my project, participant sessions were divided into 3 parts:
Review participant background (10 minutes): Go over screener responses and
1.
delve deeper into areas of interest.
Scenario based tasks (40 minutes): Evaluate user experience by asking participants
2.
to complete tasks with the paper prototype.
Wrap-up interview (10 minutes): Ask participant about their overall impressions of
3.
the product. (e.g. “How would you describe this product to a friend?)
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Paper Prototype: Usability Findings
Planning Recruiting Study Findings
2 days 3 days 1 day 1 day
Tips on study findings:
• Format will depend on your company’s goals & needs; some company’s needs
are met with a “quick findings,” others may need a detailed report with video clips.
Some top findings from my project:
• Overall: Participants liked the concept and would use it if free. (Ads were OK)
• Navigation : Understood tab structure & navigation between events.
• Content: Wanted additional info on list view and detail view (e.g. text reviews
instead of ratings alone).
• Web Site vs. iPhone: Some participants expected the app to have a sister web
site; thought certain tasks were more appropriate for desktop.
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What I didn’t learn
• While the paper prototype study was incredibly helpful in evaluating the
concept, there are many aspects of the user experience that weren’t
tested (e.g., size of targets, scrolling, swiping)
• As soon as we have a working prototype, the goal is to do another round
of usability testing with prospective users.
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References & Additional Reading
• Marc Rettig, “Prototyping for Tiny Fingers,” Communications of the ACM, April 1994
• Jakob Nielsen, “Paper Prototyping: Getting user data before you code,” http://
www.useit.com/alertbox/20030414.html
• Jared Spool, “Looking back at 16 years of paper prototyping,” http://www.uie.com/
articles/looking_back_on_paper_prototyping/
• Carolyn Snyder, “Using Paper Prototypes to Manage Risk,” http://www.uie.com/
articles/prototyping_risk/
• Matthew Klee, “Five Paper Prototyping Tips,” http://www.uie.com/articles/
prototyping_tips/
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email: suzanne@ginsburg-design.com
twitter: @suzanneginsburg
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