Technical Communication notes for 080721
Technical Communication (Eng 271-01)
Agenda for 080721
Questions
Final exam
Analysis of instructions
Overview of usability
Usability task
Group work
Questions?
Final exam?
Analysis of instructions
Draft due (tonight) Monday, July 21
Edit (?)
Final draft due Friday, July 25
Overview of usability
Texts
In the following sections, I refer to
Nielsen’s Useit.com
Nielsen & Loranger’s Prioritizing Web Usability [PWU], 2006.
Dumas & Redish’s Practical Guide to Usability Testing [PGUT], 1999.
What is usability?
Nielsen & Loranger
“Usability is a quality attribute relating to how easy something is to use. More
specifically, it refers to how quickly people can learn to use something, how
efficient they are while using it, how memorable it is, how error-prone it is,
and how much users like using it. If people can’t or won’t use a feature, it
might as well not exist.” (xvi)
Usability is defined by five quality components:
Learnability: How easy is it for users to accomplish basic tasks the first time they
encounter the design?
Efficiency: Once users have learned the design, how quickly can they perform tasks?
Memorability: When users return to the design after a period of not using it, how
easily can they reestablish proficiency?
Technical Communication notes for 080721
Errors: How many errors do users make, how severe are these errors, and how easily
can they recover from the errors?
Satisfaction: How pleasant is it to use the design?
Nielsen, Jakob. 25 August 2003. Usability 101: Introduction to usability, Usesit.com
<http://www.useit.com/alertbox/20030825.html> 24 June 2008.
Dumas & Redish
“Usability means that the people who use the product can do so quickly and
easily to accomplish their own tasks” (4).
This definition rests on four points:
1. Usability means focusing on users.
2. People use products to be productive.
3. Users are busy people trying to accomplish tasks.
4. Users decide when a product is easy to use.
Redish
Usability requires but is more than functionality,
sufficiency, reliability, and accuracy
Functionality – Does the product work
according to specifications?
Functionality
Reliability
Sufficiency
Accuracy
Sufficiency – Does it contain the needed
features?
Usability
Reliability – Does it work the same way every
time?
Accuracy – Is it trustworthy?
When should usability testing be conducted?
Dumas & Redish
“…the model for it [usability testing] was function testing, and, therefore it
usually occurred once at the end of the development process” (13)
“Usability testing is best used to diagnose problems, not to verify that all is fine.
Usability testing is best used early and often, not once at the end when it is
too late to make changes. Usability testing is best used as part of a process
that focuses on usability throughout design and development, not as the sole
time when users are considered.” (13)
Hackos & Redish
Importance of iterative usability testing in interface design
Technical Communication notes for 080721
Hackos, JoAnn, Janice Redish. 1998. User and task analysis for interface design. New York:
John Wiley & Sons, Inc. (12).
What constitutes usability testing?
Dumas & Redish (22)
1. The goal is to improve a product (document, website, etc.)
Again, note the difference between usability testing and quality assurance, which involves
checking a product to see that it meets the specifications.
2. Participants represent real users
Note that Dumas & Redish prefer participants to evaluators to subjects to users.
They also distinguish between quality assurance personal and real users.
3. Participants do real tasks
4. You observe and record participant’s actions and comments
Typically using a think-aloud protocol. Possibly using a video recorder, keystroke-tracking device,
or eye-tracking software.
5. You analyze data, diagnose problems, and recommend changes
What are the differences between a usability test and a research study?
Dumas & Redish
The goals are different
Technical Communication notes for 080721
“The goal of a research study is to test whether or not some phenomenon exists. To make that
decision, the test must be done with a sample size large enough to detect the phenomenon if it is
present.
The goal of a usability test is to uncover problems.” (36).
The participants are different
A random sample versus a convenience sample—of appropriate users (36-37).
The data is analyzed differently
Descriptive statistics (means, ranges, frequencies) versus inferential statistics (tests for statistical
significance or correlations)
How is data recorded in a usability test?
Think aloud protocol
As you complete each task, please voice your thoughts aloud: we are
interested in what you say to yourself as you perform the tasks that we give
you. In other words, say aloud everything that you say to yourself silently.
Try to act as if you were alone in the room speaking to yourself. You may also
find it useful to identify (voice aloud) the objects (buttons, icons, or links)
that you click or text that you type.
Video recordings
Eyetracking studies
Data sheets
The left column is used to identify
- Task
- Time
- Success
The data sheets are read from upper left to lower right as a record of the
evaluator’s clicks, typing, and comments
Consultants use the notes section to record evaluator’s behavior and comments
(distinguishing between quotations, paraphrases, and summaries) and to
record their own inferences
Technical Communication notes for 080721
Usability task
All MSU students are provided file space on MSU servers. Locate the MSU
webpage(s) that explain how to create a web site. Briefly assess the
usability of the page(s) that you find.
Make use of your own experience, your knowledge of your fellow MSU
students, and your knowledge of technical communication.
Group work
The following pages are screenshots (75% of actual size) taken from the
Cybex Arc Trainer 630A Owner’s Manual.
Comment on the design and content of the following pages. Make use of
material from your text and from the course chats. Use the Comment style
that I’ve provided. (Your comments should appear down the left side of the
screenshot.)
When finished,
1. delete the opening pages of this document, leaving only the screenshots and
your comments
2. insert your first names in the page header;
3. save your file as Instr_c3i_c3i_c3i.doc (replacing each “c3i” with the 3 initials
of a collaborator);
4. attach your Word file to an email message with the subject line “Eng 271 –
Cybex manual” (without the quotation marks); and
5. CC your email message to me and to each of the group members.
Your names go here
Your names go here
Your names go here
Your names go here