Krug Chapter 2
How We Really Use the Web
and
Web Site Design
Jeff Offutt
http://www.cs.gmu.edu/~offutt/
SWE 205
Software Usability and Design
Users Do Not Read the Web
• Web page authors wish users studied web sites
• No … users :
– Glance at a page
– Scan some text
– Click on the first link that looks interesting
• Web page authors …
– should not think in terms of telling a story
– should think in terms of a sign on a busy highway
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© Jeff Offutt
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Users Scan Web Pages
• Why do we use the Web in the first place?
– To save time
• Only a few pages get read completely
– And if they are more than 2 or 3 paragraphs, many
users print them
– Reading paper hurts less than reading screens
Very young people don’t notice the pain, but until
evolution adapts our eyes to reading screens,
everybody over age 25 will prefer reading ink on paper
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© Jeff Offutt
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We Compromise
• Humans do not make optimal decisions
– We take the first option that looks reasonable
• Very few people consider multiple options before
making decisions
– Especially on minor decisions
– We call people who do “great designers”
• Why do we compromise ?
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We’re in a hurry
We usually don’t lose much for guessing wrong
Comparing options doesn’t lead to better decisions
Comparing options is hard work and no fun
© Jeff Offutt
4
We Do Not Understand Fully
• Few users fully understand a system before they
start using it
• Only engineers …
• But most software developers expect users to
have full understanding
– Maybe because they are engineers ?
• Sometimes users come up with interesting ways
to use software the designers did not intend
– Users usually waste time and make mistakes
• Why ?
– Learning takes mental effort and time
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User Success Rate
• Users only find information they are
searching for on web sites about 42% of
the time
• When given an interactive task, they can
only accomplish the task about 26% of the
time !
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Web Site Home Pages
• Many web sites have a “home page” – the
introductory landmark page to the company or
organization
• Home pages should look different from interior
web pages
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No HOME button
State purpose of the entire web site
Provide a directory of the web site
Include a search facility
• All interior web pages must link to the home page
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Search Boxes
• More than 50% of users start by searching
• The search should be in the web site
– Not the entire WWW
• Make search available on all pages
• People do not understand boolean:
“I’m interested in SWE 205 and CS 332” should be:
• 205 OR 332
but most people will enter:
• 205 AND 332
Do not ask for boolean operators in search
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© Jeff Offutt
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Screen Width
• Try not to design to a specific width – keep
the HTML as flexible as possible
• Users do not like to scroll horizontally
– Put information that is not very important on
the right
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URL Design
Unfortunately, we must type and remember URLs
• Help the users avoid typos:
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Do not use upper case in domain, directory, or file names
Underscores require the shift key – hyphens are better, but not much
Avoid zeros (0 or O?) and ones (1 or l)?
Do not add unnecessary directories
Choose short, common words
Use standard abbreviations
• Use URL aliasing to be error tolerant :
– Allow x.com and www.x.com
– Provide aliases for common misspellings (jeffoffutt.com and jeffoffut.com)
• Use the standard “html”, not the non-standard “.htm”
• Fully specify URLs in HTML links:
– Do not use this: cs.gmu.edu/~offutt
– Do use this:
https://www.cs.gmu.edu/~offutt/
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Summary
Professional HTML designers have
accumulated these pearls of wisdom over
many, painful, years
Standards documents give these rules
I also want you to understand WHY
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© Jeff Offutt
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