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Related Content: CS101 - VU Lectures, Handouts, PPT Slides, Assignments, Quizzes, Papers & Books of Introduction to Computing
Web Design for Usability
During the last lecture …:
We looked at the role of heuristics in architectural (or high-level) design
We also became familiar with a few popular design heuristics
Heuristic:
Rule of thumb learned through trial & error
Common sense lesson drawn from experience
Caution! Caution!
Heuristics don’t always lead to the best results
At times they even lead to the wrong ones, but mostly to results that are good-enough
USABILITY
Today’s Goal:
Web Design for Usability
To become able to appreciate the role of usability in Web design
To become able to identify some of the factors affecting the usability of a Web page
What’s a Good Site?
The one that achieves the result that it was designed forGenerally, that result can only be
achieved by giving the user what s/he wants, as quickly as possible, without her/him
expending much effortOne definition of usability: Let the user have what s/he wants,
quickly, without much effort“Quickly” is important!
SPEED:
Users don't read; they scan
Users don't make optimal choices; they look for the first good-enough solution
Users don't figure out how things work; they muddle through
Design is Important!
62% of shoppers gave up looking for the item they wanted to buy online (Zona
Research)
40% visitors don’t return to a site if their first visit was a -ive experience (Forrester
Research)
83% of users have left sites in frustration due to poor navigation, slowness (NetSmart
Research)
Simple designs have greater impact: they can be understood immediately! (Mullet/Sano)
Designs should be consistent & predictable (unified)
Elements of Website Design:
Navigation scheme
Layout of information
Overall look and feel
Website Navigation:
The interface/controls that a Website provides to the user for accessing various parts of
the Website
It probably is the most important aspect of the design of a Website
A Few Navigation Design Heuristics:
Put the main navigation on the left of the page
It should be ‘invisible’ until it is wanted
It should require an economy of action & time
It should remain consistent
Use text for navigation labels. If you must use icons, put a description underneath each
icon
Navigation Design Heuristics (contd.):
Labels should be clear, understandable
Labels should be legible
Do not play with standard browser buttons & features
Provide search capability
Good designs assist the user in recovering from errors
Assisting the User Recover from Errors:
Location, post code mismatch
Credit card number errors
Phone numbers
Spelling errors
A few constructive recommendations
Let’s look at a few Web sites and see how we can improve their usability
Enter
Dragon’s Lair
Making Display Elements Legible:
Designing (arranging) Display Elements
Elements must be large enough to be processed visually
Elements must contrast sufficiently with their backgrounds
Making Display Elements Legible:
Related elements should be visually grouped through the use of space, color, or graphical
boundaries
The relative levels of importance among elements in a display should be revealed
graphically
Ensuring Text is Readable:
Use sans serif (e.g. Arial, Helvetica, Verdana) typefaces for display on screen
Display type intended for continuous reading at 10 to 14 points
Avoid the overuse of bold and italics
Avoid setting type in all caps
Arrange type intended for extended reading flush left, ragged right
Avoid lines of type shorter than 40 characters and longer than 60 characters
Mark the boundaries between paragraphs with blank lines rather than indentation
Use headings and subheadings to visually reveal the relationships among text elements
they label – paragraphs after paragraphs of text do not work that well on the Web
Using Pictures & Illustrations:
Avoid using pictures that are strictly decorative
Using Motion
Use motion to attract the viewer’s attention
Avoid the use of motion for “cosmetic” purposes
Success is defined by the user, not the builder
In Today’s Lecture:
We looked at the role of usability in Web site design
We identified some of the factors affecting the usability of a Web page
Next Lecture:
Computer Networks
We will become able to appreciate the role of networks in computing
We will familiarize ourselves with various networking topologies and protocols
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