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Design of Everyday Things
Agenda
Questions? Project Part 1: Now what? Test review One last bit on prototyping Design of Everyday Things
What to do now
Start brainstorming!!– Lots of ideas, then narrow down to 3 or 4
Explore design space– Vary what you can – hardware, forms of input, forms of output,
features, requirement priorities, usability priorities
Be off the wall, crazy– This will lead to less crazy but original ideas
Project poster – October 20 Project report + prototype: Nov. 10
Midterm review
How to study:– Look at slides for topics, bullets, vocabulary, etc.– Find details and examples in the books as
needed
Test format– 25-50% true/false, multiple choice, fill-in-blank– Rest short answer, probably with one longer
answer
Review
What is usability? What is design? Why is it hard? The user centered design process
– General steps– various models – high level understanding– Waterfall vs. other models
Requirements Review
Functional vs. non functional Summative eval vs. formative eval What pieces are part of this?
– User characteristics, task analysis, environment, etc.etc. – Persona – what is it and what makes a good one?– Scenario – what is it and what makes a good one?– Stakeholders (primary, secondary, tertiary, facilitating)
How do you gather data? Tradeoffs?– Interview, questionnaire, observation, etc. etc.
Task models– Hierarchical task analysis - how to do it?– Other models – what can they represent?
Humans review
What are issues concerning our senses? Model Human Processor model of memory
– What are pieces of memory (STM, LTM, etc.)– What’s a chunk? Why do we care?– What are implications? (recognition over recall,
etc.)
Other processes – what are they? (attention, learning)– What are the implications?
Interaction Review
Command line WIMP Direction manipulation Pen & mobile Speech & natural language
Issues, advantages, disadvantages, etc.
Prototyping
Prototyping– What’s vertical vs. horizontal?– What’s low vs. high fidelity?– What are various methods?
Scenarios, mockups/sketches, etc. Issues and tradeoffs?
Prototyping Technique
Wizard of Oz - Person simulates and controls system from “behind the scenes”– Use mock interface and
interact with users– Good for simulating
system that would be difficult to build
Can be either computer-based or not
Wizard of Oz
Method:– Behavior should be algorithmic– Good for voice recognition systems
Advantages:– Allows designer to immerse oneself in situation– See how people respond, how specify tasks
Review
Low-fidelity Medium-fidelity High-fidelity
Sketches, mock-ups Slide shows
Simulations
System prototypes
Scenarios
Storyboards
For more: take ITIS 3150
Rapid Prototyping and Interface Building Offered next fall
Summary
Darn these hooves!I hit the wrong switch again!Who designs these instrumentPanels, raccoon?!
Don Norman
Professor at Northwestern and Principal of Nielsen Norman group
Previously Professor at UCSD, senior positions at Apple & HP
ACM/CHI Lifetime Achievement Award
Prolific author http://www.jnd.org/
Discussion
What did you take away from DOET book so far?
Here are some
Affordances are important Minimize the gulf of interpretation and gulf of
execution Use natural mappings Make state visible Use a conceptual model that makes sense Provide feedback
Daily Challenges
How many of you can use all the functionality in your– VCR– Digital watch– Copy machine– Stereo system– Plumbing fixtures
Hall of Shame Example
Leitz slide projector– To move forward, short press– To move backward, long press
What happens when you get frustrated?
Fun Examples
Phones
How do you- transfer a call- change volume- store a number- ...
Changing Ringer Volume
Press “Program” Press “6” Set volume
– Low - Press “1”– Medium - Press “2”– High - Press “3”
Press “Program”
Much better…
Important Concepts
Affordances Visibility Conceptual models Mapping Feedback Constraints
Affordances
Perceived and actual properties of an object that determine how it could be used– Chair is for sitting– Button is for pushing– Door handle is for ….– Scroll arrow is for …– Icon is for …
Door Opening Affordances
1 2 3 4 5
6 7
Which doors are easy to open?
Which doors are hard to open?
Why?
Affordances in interfaces
Interfaces are virtual and do not have ‘real’ affordances like physical objects
Interfaces have ‘perceived’ affordances– Learned conventions of arbitrary mappings
between action and effect at the interface– Some mappings are better than others
Mantra
Complex things may need explanation, but simple things should not– If a simple thing requires instructions, it is likely a
failed design
Norman’s 2 main principles– Provide a good conceptual model– Make things visible
Affordances is part of this
Conceptual Models
People build their own systems of how things work– Example - thermostat
Designer can help user foster an appropriate conceptual model– Appearance, instructions, behavior...
Conceptual Models
Mental models are not always right Two Classes:
– Functional model Stimulus - response “Press the accelerator once, then turn the key” At surface or superficial level
– Structural model Deeper sense of why it happens, not just what happens “Press the accelerator to engage the automatic choke on a
carburetor”
Visibility
When functionality is hidden, problems in use occur– Occurs when number of functions is greater than
number of controls
When capabilities are visible, it does not require memory of how to use– Recognition over Recall– in the world vs. in the head
Simple Example
Bathroom faucets– Two functions
Hot/cold Flow
Bathroom Faucets 1
Can you figureout how to useit?
Are two functionsclear and independent?
Bathroom Faucets 2
Can you figureout how to useit?
Are two functionsclear and independent?
Bathroom Faucets 3
Can you figureout how to useit?
Are two functionsclear and independent?
My parent’s microwave
5:45
My microwave
About that VCR…
That old joke - “how many of you have a VCR that is blinking 12:00?” :-)
Still true today :-(
Which is Faster for Setting Time?
Mapping
Relationship between control and action/result in the world
Take advantage of physical analogies or cultural understandings– Good:
Car, various driving controls Mercedes Benz seat adjustment example
– Bad Car stereo - Knob for front/back speakers
Which is better?
or
Mapping Example: Euros
Size::value
Mapping Example: Stove
Which controls which?
Why not this?
Yikes!
Why Not Design Better
Stove
Speakers
Physical, monetary,convenience, etc.,constraints dictateotherwise
Feedback
Sending information back to the user about what has been done
Includes sound, highlighting, animation and combinations of these
– e.g. when screen button clicked on provides sound or red highlight feedback:
“ccclichhk”
Execution-Evaluation cycle
Norman (DOET, p. 46)
UserGoals
PhysicalSystem
Gulfof
Execution
Gulfof
Evaluation
Goals, Execution, Evaluation
Physical System
GoalsWhat we
want to happen
ExecutionWhat we
do to the world
EvaluationComparing what happened
with what we wanted to happen
(Gulf of Execution) (Gulf of Evaluation)
Execution
GoalsWhat we
want to happen
An intention to actso as to achieve the goal
The actual sequence of actionsthat we plan to do
The physical execution of that action sequence
Physical System
Evaluation
GoalsWhat we
want to happen
Evaluation of the interpretationswith what we expected to happen
Interpreting the perception accordingto our expectations
Perceiving the stateof the world
Physical System
Seven Stages - All Together
GoalsWhat we
want to happen
Evaluation of the interpretationswith what we expected to happen
Interpreting the perception accordingto our expectations
Perceiving the stateof the world
An intention to actso as to achieve the goal
The actual sequence of actionsthat we plan to do
The physical execution of that action sequence
Physical System
Implications – Which Gulf does these Address?
Make current state and action alternatives visible
Need good conceptual model with consistent system image
Interface should include mappings that reveal relationships between stages
User should receive continuous feedback Provide affordances
Goal: Minimize Gulfs
Gulf of Execution– Conceptual model– Affordances– Natural mappings
Gulf of Evaluation– Make state visible– Feedback
Try and Try Again
Norman thinks that it often takes 5 or 6 tries to get something “right”
Simply may not have that luxury in a competitive business environment