Website Usability

1
Website Usability

• Presented by
• Hezeng Li
• CS Department
• UA

2
Main Content

• Introduction
• What is website usability
• Why website usability
• Why everybody designs web sites incorrectly
  
• How to Design a Good Website
• Most common website design mistakes
• Bad examples
• General design guidelines
• A possible better website design method
• Website Usability Testing
• Two main methods for testing
• Testing steps
• How many users needed
• Testing cost
• Conclusions
• Conclusions
• Further study

3
Introduction

• What is website usability
• Web usability is the efficient, effective
  and satisfying completion of a specified task by
  any given Web user
• Why website usability
• (1)10 million sites on the Web by January
  2000
• (2) Usability is important in the Internet
  economy
• (3) In product and software design,
  customers pay
• first, On the Web, users experience
  usability
• first, and pay later
• Why everybody designs web sites incorrectly
• Dr. Nielsens observations
• (1) User centric design rather than
  corporate centric
• design
• (2) Design for an optimal user experience
  under real
• estate conditions

4
How to Design a Good Website
 

• Most common website design mistakes

5
How to Design a Good Website(Continued)

• Bad examples
•  http//www.ua.edu/
• Go to current student, click schedule of
  classes
•  http//www.lib.ua.edu/
• Go to library catalogue, click search by
  title
•  http//chicagotribune.com/
• From selection window select news, then
  Go
• http//www.acm.org/
• ClickACM1 or http//www.acm.org/cacm
• http//www.useit.com/jakob/

6
How to Design a Good Website(Continued)

• General design guidelines
• (1) Develop your content first in plain
  text, then
• you can easily develop separate pages
• (2) Provide a text equivalent for every
  non-text
• element
• (3) Make sure that all of your information
  is
• conveyed by context and not by color
• (4) Use correct and validated HTML. Don't
  use
• browser-specific elements
• (5) Provide easy-to-use navigation
• (6) Minimize the use of dynamic contents
• (7) Use client-side image maps instead of
  server-
• side image maps
• (8) If you use data tables, identify row and
  column
• headers

7
How to Design a Good Website(Continued)

• (9) If you must use frames, use the noframes
  
• option to provide a plain text
  alternative to your
• page
• (10) If your site uses multimedia, provide a
• description and download instructions
• (11) If you use shockwave or flash
• provide users with a quick way to
  bypass them
• (12) Don't hold your users hostage by refusing
  to let
• them "back" out of your site

8
How to Design a Good Website(Continued)

• A possible better website design method
• Three dimensions website
• (1) The same size screen can show more
• information
• (2) The three dimensional interface is more
  vivid
• than that of two dimensions
• (3) Objects represented by three dimensions
  are
• much clearer than that represented by
  two
• dimensions.
• (4) It is more suitable for education than
  two
• dimensions websites
• (5) It is good for the people who has
  limited
• reading ability

9
Website Usability Testing

• Checklist-based testing
• (1) Preliminary self-appraisal
• (2) Provide checklists to your testers
• (3) Provide some brief instructions
• (4) Leave
• Scenario-based testing
• (1) presenting representative end-users with
• scenarios designed to cover the major
• functionality
• (2) Results are then tabulated
• (3) During the test the testers are
  available to assist
• participants

10
Website Usability Testing(continued)

• Testing steps
• (1) Plan
• Purpose and audience of site
• Usability goals
• Tasks
• Participants
• Materials
• Setting
• (2) Do
• Introduction for participant
• Watch quietly
• Take notes
• Interact with participant
• Debriefing, questionnaire

11
Website Usability Testing(continued)

• Testing steps(continued)
• (3) Follow-up
• Tabulate data
• Findings
• Recommendations
• Actions
• How many users needed
• The number of usability problems found with
  n users is
•  
• N(1-(1-L)n)
•  
• where N is the number of usability
  problems discovered in the design and L is the
  proportion of usability problems discovered while
  testing a single user. The typical value of L is
  31.

12
Website Usability Testing(continued)

• How many users needed

13
Website Usability Testing(continued)

• Testing cost
• 0 do-it-yourself, no-budget, invest
  time
• 2k low budget, do-it-yourself
• 20k hire out usability testing,
  portable lab
• 100k fancy lab
• Compare with Fortune 1000s spending 2
• mil/year on redesigns

14
Conclusions

• the guidelines and the testing do not guarantee
  you can get a good website
• Five users are enough for website usability
  testing

15
Further study

• Three dimension website could be one potential
  research area.

16
References

• Alfred T. Lee, SIGCHI Bulletin Volume 31, Number
  1 January 1999 P38.
• Jakob Nielsen, Designing Web Usability, New
  Riders Publishing, Indianapolis, 2000.
• Christian Osterbauer, Monika Köhle, Thomas
  Grechenig, WEB USABILITY TESTING.
  http//alpha.swt.tuwien.ac.at/publications/papers/
  ausweb2k/paper.html.
• Terry Brainerd Chadwick, General Usability -- An
  Information Seeker's Perspective,
  http//www.tbchad.com/Usability/general_usability.
  html
• Keith Instone, http//instone.org/keith/howtotest/
  index.html.
• Jakob Nielsen, http//www.useit.com/alertbox/20000
  319.html
• Loren Miller, http//ioxy.com/web3d.html.
• Chandran-Dudley, http//www.dpa.org.sg/DPA/publica
  tion/dpadec98/p11.htm.
•  
•