Chapter 1: Usability of Interactive Systems
Discussion Topics with Answers
1. Devise an outline, consistent with the scientific method, which interface
researchers should follow to validate their designs.
Following the scientific method closely works very well in usability studies.
Identify a “control”, formulate a hypothesis, test for hypothesis being true or
false, etc. is an ideal model for interface researchers.
2. List some characteristics of successful user interface designers with respect to
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their approach to solving UI problems
– Successful UI designers go beyond vague notions of “user friendliness”,
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“intuitive”, and “natural” doing more than simply making checklists of
subjective guidelines.
– They have a thorough understanding of the diverse community of users
and the tasks that must be accomplished.
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– They study evidence-based guidelines and pursue the research literature
when necessary.
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– They are deeply committed to enhancing the user experience, which
strengthens their resolve when they face difficult choices, time pressures,
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and tight budgets
– Are aware of the importance of eliciting emotional responses, attracting
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attention with animations, and playfully surprising users
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3. As noted in the book, some skeptics feel that accommodating diversity requires
dumbing-down or lowest-common-denominator strategies. However, the
authors claim that in their experience, rethinking interface designs to
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accommodate these diversity situations will result in a better product for all
users. Give an example of a product that meets the specific needs of a certain
group of people, yet gives all users a better experience.
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One answer could be Automated Teller Machines (ATM) seen in ethnically
diverse neighborhoods, allowing the user to select the language before
continuing to interact with the machine. Chapter 6 goes into detail via a Case
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Study on ATM design.
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4. List several reasons why certain people resist using computers and suggest
possible ways to you can alleviate these concerns.
One could argue that a major limitation is the complexity of the interfaces
combined with small screens and fonts. Many persons are just not able to
comfortable select a tiny item from a drop down list with a mouse, and, to
many, that still is a difficult concept to grasp: to hold the mouse button down
when selecting an item as well as knowing when to release the button is a bit
complex to the novice. Solutions could be touch-screen (mouse-less) designs
with large font sizes.
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,5. Suggest three usability measures that can be directly used to produce a
practical evaluation of a system. Keep the goals of efficiency and satisfaction in
mind with these measures.
Examples: Time to learn, rate of human errors, speed of task completion,
subjective satisfaction, sales, human retention over time.
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,Chapter 2: Universal Usability
Discussion Topics with Answers
1. Describe three populations of users with special needs. For each of these
populations, suggest three ways current interfaces could be improved to better serve
them.
Elderly, very young, not computer savvy. Some of this work has begun by
tailoring control panels for Windows and Mac interfaces, e.g. default font
sizes. There is still much work to do regarding introduction to computers. The
One Laptop Per Child initiative is a start for two of the three items listed here.
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2. Suppose you need to design a system for users in both the United States and Japan.
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Present a list of cultural differences that you should be aware of so that a successful
design can be made.
There are a number of references on internationalization of user interfaces.
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Not only the difference in the languages, but cultural differences need to be
considered. Usability testing with both U.S. and Japanese users is a must. A
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classic reference is “International User Interfaces” by Elisa M. del Galdo and
Jakob Nielsen. Another is available at:
http://www.amanda.com/cms/uploads/media/AMA_GlobalizationUserInterfaceDesignWeb.pdf
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3. In certain interfaces, it is necessary to inform users of an abnormal condition or
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time-dependent information. It is important that the display of this information
catches the user's attention. Suggest five ways a designer can successfully attract
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attention.
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Consider an air traffic control system operator display with an alert condition
of two planes being too close to each other. One can alert an operator by
changing the color displayed for the plane’s identification information, using a
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warning that pops-up, using a warning that flashes on/off, an audible beep, or
a constant audio alarm. Certainly usability testing these proposed solutions
with real air traffic controllers so designers can trade-off successfully
attracting the attention of the operator vs. causing one to totally lose their
train of thought and make conditions worse.
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4. Name a piece of software you often use where it is easy to produce an error. Explain
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ways you could improve the interface to better prevent errors.
Not to mention names, but some desktop operating system vendors do
publish updates to their products without fully testing their changes,
sometimes causing more difficulty than not making the change in the first
place. My suggestion would be to use a beta test group more often of people
who are committed to responding with timely, incisive feedback before the
change is released to the general population.
5. List some human physiological or psychological factors that can influence human
operator performance.
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, Variations in physical abilities and physical workplaces, diverse cognitive and
perceptual abilities, personality types, and factors affecting perceptual and
motor performance, such as:
‒ Arousal and vigilance
‒ Fatigue and sleep deprivation
‒ Perceptual (mental) load
‒ Knowledge of results and feedback
‒ Monotony and boredom
‒ Sensory deprivation
‒ Nutrition and diet
‒ Fear, anxiety, mood, and emotion
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‒ Stress
‒ Drugs, smoking, and alcohol
‒ Physiological rhythms
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