1. Krug Chapter 2 How We Really Use the Web and Web Site Design
Jeff Offutt
SWE 205
Software Usability and Design

2. Users Do Not Read the Web
Web page authors want users to study 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
21-Nov-18
© Jeff Offutt

3. Why do we use the Web in the first place?
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
21-Nov-18
© Jeff Offutt

4. Humans do not make optimal decisions
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 ?
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
21-Nov-18
© Jeff Offutt

5. 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
Don’t make me think!
21-Nov-18
© Jeff Offutt

6. User Success Rate
Users only find information they search 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 !
21-Nov-18
© Jeff Offutt

7. Home pages should look different from interior web pages
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
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
21-Nov-18
© Jeff Offutt

8. Do not ask for boolean operators in search
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
21-Nov-18
© Jeff Offutt

9. Users do not like to scroll horizontally
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
21-Nov-18
© Jeff Offutt

10. Unfortunately, we must type and remember URLs
URL Design
Unfortunately, we must type and remember URLs
Help the users avoid typos:
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
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:
21-Nov-18
© Jeff Offutt

11. Summary
Professional HTML designers have accumulated these pearls of wisdom over many, painful, years
Standards documents give some of these rules
I also want you to understand WHY
21-Nov-18
© Jeff Offutt